ASTM E10-23

Standard Test Method for Brinell Hardness of Metallic Materials

SIGNIFICANCE AND USE
4.1 The Brinell hardness test is an indentation hardness test that can provide useful information about metallic materials. This information may correlate to tensile strength, wear resistance, ductility, or other physical characteristics of metallic materials, and may be useful in quality control and selection of materials.  
4.2 Brinell hardness tests are considered satisfactory for acceptance testing of commercial shipments, and have been used extensively in industry for this purpose.  
4.3 Brinell hardness testing at a specific location on a part may not represent the physical characteristics of the whole part or end product.
SCOPE
1.1 This test method covers the determination of the Brinell hardness of metallic materials by the Brinell indentation hardness principle. This standard provides the requirements for a Brinell testing machine and the procedures for performing Brinell hardness tests.  
1.2 This test method includes requirements for the use of portable Brinell hardness testing machines that measure Brinell hardness by the Brinell hardness test principle and can meet the requirements of this test method, including the direct and indirect verifications of the testing machine. Portable Brinell hardness testing machines that cannot meet the direct verification requirements and can only be verified by indirect verification requirements are covered in Test Method E110.  
1.3 This standard includes additional requirements in the following annexes:    
Verification of Brinell Hardness Testing Machines  
Annex A1  
Brinell Hardness Standardizing Machines  
Annex A2  
Standardization of Brinell Hardness Indenters  
Annex A3  
Standardization of Brinell Hardness Test Blocks  
Annex A4  
1.4 This standard includes nonmandatory information in the following appendixes that relates to the Brinell hardness test:    
Table of Brinell Hardness Numbers  
Appendix X1  
Examples of Procedures for Determining
Brinell Hardness Uncertainty  
Appendix X2  
1.5 At the time the Brinell hardness test was developed, the force levels were specified in units of kilograms-force (kgf). Although this standard specifies the unit of force in the International System of Units (SI) as the Newton (N), because of the historical precedent and continued common usage of kgf units, force values in kgf units are provided for information and much of the discussion in this standard refers to forces in kgf units.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Jun-2023
• ICS: 77.040.10 - Mechanical testing of metals
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.06 - Indentation Hardness Testing

Relations

• Refers: ASTM A833-19 - Standard Test Method for Indentation Hardness of Metallic Materials by Comparison Hardness Testers
• Effective Date: 01-Nov-2019
• Refers: ASTM A1038-19 - Standard Test Method for Portable Hardness Testing by the Ultrasonic Contact Impedance Method
• Effective Date: 01-Oct-2019
• Refers: ASTM A1038-17 - Standard Test Method for Portable Hardness Testing by the Ultrasonic Contact Impedance Method
• Effective Date: 01-Nov-2017
• Refers: ASTM A833-17 - Standard Test Method for Indentation Hardness of Metallic Materials by Comparison Hardness Testers
• Effective Date: 01-Nov-2017
• Refers: ASTM A833-08a(2014) - Standard Practice for Indentation Hardness of Metallic Materials by Comparison Hardness Testers
• Effective Date: 01-Oct-2014
• Refers: ASTM A1038-13e1 - Standard Test Method for Portable Hardness Testing by the Ultrasonic Contact Impedance Method
• Effective Date: 01-Nov-2013
• Refers: ASTM A1038-13 - Standard Test Method for Portable Hardness Testing by the Ultrasonic Contact Impedance Method
• Effective Date: 01-Nov-2013
• Refers: ASTM E74-13a - Standard Practice of Calibration of Force-Measuring Instruments for Verifying the Force Indication of Testing Machines
• Effective Date: 01-May-2013
• Refers: ASTM E74-13 - Standard Practice of Calibration of Force-Measuring Instruments for Verifying the Force Indication of Testing Machines
• Effective Date: 01-Mar-2013
• Refers: ASTM E74-12 - Standard Practice of Calibration of Force-Measuring Instruments for Verifying the Force Indication of Testing Machines
• Effective Date: 01-Dec-2012
• Refers: ASTM B647-10 - Standard Test Method for Indentation Hardness of Aluminum Alloys by Means of a Webster Hardness Gage
• Effective Date: 01-Dec-2010
• Refers: ASTM A1038-10a - Standard Test Method for Portable Hardness Testing by the Ultrasonic Contact Impedance Method
• Effective Date: 01-Nov-2010
• Refers: ASTM A1038-10 - Standard Practice for Portable Hardness Testing by the Ultrasonic Contact Impedance Method
• Effective Date: 15-May-2010
• Refers: ASTM E384-10e1 - Standard Test Method for Knoop and Vickers Hardness of Materials
• Effective Date: 01-Feb-2010
• Refers: ASTM E384-10 - Standard Test Method for Microindentation Hardness of Materials
• Effective Date: 01-Feb-2010

Overview

ASTM E10-23: Standard Test Method for Brinell Hardness of Metallic Materials establishes procedures for determining the Brinell hardness of metals using the Brinell indentation hardness test method. This widely recognized standard, developed by ASTM, defines the requirements for both stationary and portable Brinell hardness testing machines, the use of approved indenters, recommended test forces, and the procedures to ensure consistent, accurate hardness measurements for metallic materials.

Brinell hardness testing provides valuable information about a metal's mechanical properties, such as correlation to tensile strength, wear resistance, ductility, and suitability for specific applications. As a mainstay in material selection and quality control, this test method is essential for industries requiring reliable data on metal performance.

Key Topics

• Brinell Hardness Test Principle: The method involves pressing a tungsten carbide ball indenter of specified diameter into the test material with a defined force, holding it for a specified time, and then measuring the resultant indentation diameter. The Brinell hardness number (BHN or HBW) is calculated based on the force and the indentation's surface area.
• Equipment and Calibration: The standard outlines equipment requirements for both stationary and portable Brinell hardness testing machines, including regular direct, indirect, and daily verifications to ensure accurate and traceable results.
• Testing Procedure: Detailed instructions are given for preparing specimens, selecting correct test parameters (indenter size, force, dwell time), performing the indentation, measuring results, and reporting findings.
• Specimen Preparation: Guidance is provided on minimum material thickness, surface preparation, and necessary specimen dimensions to achieve valid results.
• Verification and Standardization: Annexes include requirements for verifying machines, standardizing indenters, and establishing test blocks for consistent hardness measurement.
• Reporting Requirements: The standard specifies the necessary information for test reports, including test conditions, measurement devices, and notation for portable testing (HBW/P).
• Converted Hardness Values: While conversion between Brinell and other hardness scales is possible, such values are only approximate and should be reported alongside the original measurement.

Applications

The ASTM E10-23 Brinell hardness test is extensively applied across many sectors:

• Quality Control in Manufacturing: Used for acceptance testing of metallic parts and raw materials, ensuring consistency and mechanical suitability.
• Material Selection: Hardness values aid engineers and designers in choosing appropriate metals for applications requiring specific strength, wear resistance, or ductility.
• Inspection of Large or Assembled Components: Portable Brinell testers allow in-situ hardness testing on heavy or installed equipment where fixed machines cannot be used.
• Research and Development: Brinell hardness is used to evaluate new alloys, surface treatments, or heat treatment processes.
• Compliance and Certification: Brinell testing is required for commercial shipments and is referenced in contractual and procurement standards worldwide.

Related Standards

• ASTM E110: Test Method for Rockwell and Brinell Hardness of Metallic Materials by Portable Hardness Testers
• ASTM E140: Hardness Conversion Tables for Metals - Provides conversion relationships among Brinell, Rockwell, Vickers, Knoop, Leeb, and other hardness scales
• ASTM E384: Test Method for Microindentation Hardness of Materials
• ASTM A956: Leeb Hardness Testing of Steel Products
• ISO/IEC 17025: General Requirements for Competence of Calibration and Testing Laboratories - Ensures traceability and reliability of laboratory testing
• ISO/IEC 17011: Conformity Assessment General Requirements for Accreditation Bodies

Summary

ASTM E10-23 is a crucial international standard for determining Brinell hardness of metallic materials. Its detailed procedures enable users to achieve accurate, repeatable, and traceable hardness measurements essential for quality assurance, material selection, and compliance in a wide range of industries. The Brinell method’s robust applicability and standardized approach make it fundamental for anyone involved in metallic materials testing and evaluation.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E10 − 23 American Association State Highway
and Transportation Officials Standard
AASHTO No.: T70–86
Standard Test Method for
Brinell Hardness of Metallic Materials
This standard is issued under the fixed designation E10; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This test method covers the determination of the Brinell
responsibility of the user of this standard to establish appro-
hardness of metallic materials by the Brinell indentation
priate safety, health, and environmental practices and deter-
hardness principle. This standard provides the requirements for
mine the applicability of regulatory limitations prior to use.
a Brinell testing machine and the procedures for performing
1.7 This international standard was developed in accor-
Brinell hardness tests.
dance with internationally recognized principles on standard-
1.2 This test method includes requirements for the use of
ization established in the Decision on Principles for the
portable Brinell hardness testing machines that measure Brinell
Development of International Standards, Guides and Recom-
hardness by the Brinell hardness test principle and can meet the
mendations issued by the World Trade Organization Technical
requirements of this test method, including the direct and
Barriers to Trade (TBT) Committee.
indirect verifications of the testing machine. Portable Brinell
hardness testing machines that cannot meet the direct verifica-
2. Referenced Documents
tion requirements and can only be verified by indirect verifi-
2.1 ASTM Standards:
cation requirements are covered in Test Method E110.
A833 Test Method for Indentation Hardness of Metallic
1.3 This standard includes additional requirements in the
Materials by Comparison Hardness Testers
following annexes:
A956/A956M Test Method for Leeb Hardness Testing of
Verification of Brinell Hardness Testing Machines Annex A1
Steel Products
Brinell Hardness Standardizing Machines Annex A2
A1038 Test Method for Portable Hardness Testing by the
Standardization of Brinell Hardness Indenters Annex A3
Ultrasonic Contact Impedance Method
Standardization of Brinell Hardness Test Blocks Annex A4
B647 Test Method for Indentation Hardness of Aluminum
1.4 This standard includes nonmandatory information in the
Alloys by Means of a Webster Hardness Gage
following appendixes that relates to the Brinell hardness test:
E29 Practice for Using Significant Digits in Test Data to
Table of Brinell Hardness Numbers Appendix X1
Determine Conformance with Specifications
Examples of Procedures for Determining Appendix X2
Brinell Hardness Uncertainty E74 Practices for Calibration and Verification for Force-
Measuring Instruments
1.5 At the time the Brinell hardness test was developed, the
E110 Test Method for Rockwell and Brinell Hardness of
force levels were specified in units of kilograms-force (kgf).
Metallic Materials by Portable Hardness Testers
Although this standard specifies the unit of force in the
E140 Hardness Conversion Tables for Metals Relationship
International System of Units (SI) as the Newton (N), because
Among Brinell Hardness, Vickers Hardness, Rockwell
of the historical precedent and continued common usage of kgf
Hardness, Superficial Hardness, Knoop Hardness, Sclero-
units, force values in kgf units are provided for information and
scope Hardness, and Leeb Hardness
much of the discussion in this standard refers to forces in kgf
E384 Test Method for Microindentation Hardness of Mate-
units.
rials
This test method is under the jurisdiction of ASTM Committee E28 on
Mechanical Testing and is the direct responsibility of Subcommittee E28.06 on
Indentation Hardness Testing. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2023. Published August 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1924. Last previous edition approved in 2018 as E10 – 18. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0010-23. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E10 − 23
TABLE 1 Symbols and Designations
2.2 American Bearings Manufacturer Association Stan-
dard: Symbol Designation
ABMA 10-1989 Metal Balls D Diameter of the ball, mm
2.3 ISO Standards:
F Test force, N
ISO/IEC 17011 Conformity Assessment—General Require-
F Test force, kgf
ments for Accreditation Bodies Accrediting Conformity kgf
Assessment Bodies 1
F 5 × F
kgf
g
ISO/IEC 17025 General Requirements for the Competence n
of Calibration and Testing
where g is the acceleration due to gravity.
n
g = 9.80665 N/kgf
n
3. Terminology and Equations
d Diameter value of the indentation, mm
3.1 Definitions:
d 1 1d 2 1{1d N
s d s d s d
3.1.1 calibration—determination of the values of the sig-
d 5
N
nificant parameters by comparison with values indicated by a
reference instrument or by a set of reference standards. where d(1), d(2) . d(N) are the measured indentation
diameters in mm, and N is the number of diameter mea-
3.1.2 verification—checking or testing to assure confor-
surements (typically 2).
mance with the specification.
h Depth of the indentation, mm
3.1.3 standardization—to bring in conformance with a
2 2
D 2 D 2 d
œ
known standard through verification or calibration.
h 5
3.1.4 Brinell hardness test—an indentation hardness test
using a verified machine to force an indenter (tungsten carbide
Force-
ball with diameter D), under specified conditions, into the F
kgf
Diameter
D
surface of the material under test. The diameter of the resulting
ratio
indentation d is measured after removal of the force.
HBW Brinell hardness
3.1.5 Brinell hardness number—a number, which is propor-
tional to the quotient obtained by dividing the test force by the
Test Force
Surface area of indentation
curved surface area of the indentation which is assumed to be
spherical and of the diameter of the ball.
2F
kgf
3.1.6 Brinell hardness scale—a designation that identifies
2 2
π D sD 2 D 2 d d
œ
the specific combination of ball diameter and applied force
used to perform the Brinell hardness test.
3.1.7 Brinell hardness testing machine—a Brinell hardness
machine used for general testing purposes.
machine that is designed to move into the testing position prior
3.1.8 Brinell hardness standardizing machine—a Brinell
to a test, (for example, securely fixed to a moving support arm),
hardness machine used for the standardization of Brinell
and has been previously verified to ensure that such moves will
hardness test blocks. The standardizing machine differs from a
not affect the hardness result.
regular Brinell hardness testing machine by having tighter
3.2 Equations:
tolerances on certain parameters.
3.2.1 The Brinell hardness number is calculated as:
3.1.9 force-diameter ratio—a number calculated as the ratio
2F
kgf
of the test force in kgf to the square of the indenter ball
HBW 5 (1)
2 2
πD~D 2 =D 2 d !
diameter in mm (see Table 1).
3.1.10 portable Brinell hardness testing machine—a Brinell
where:
hardness testing machine that is designed to be transported,
F = test force in kgf,
kgf
carried, set up, and operated by the users, and that measures
D = diameter of the indenter ball in mm, and
Brinell hardness by the Brinell hardness test principle.
d = measured mean diameter of the indentation in mm
(see Table 1).
3.1.11 movable Brinell hardness testing machine—a Brinell
hardness testing machine that is designed to be moved to
¯
3.2.2 The average mean diameter d of a set of n indentations
different locations on a moveable frame, table or similar
is calculated as:
support that is integral to the testing machine (for example,
d 1d 1…1d
securely fixed to a rolling table), or a Brinell hardness testing
1 2 n
¯
d 5 (2)
n
where:
Available from American Bearing Manufacturers Association (ABMA), 1001
N. Fairfax Street, Suite 500 Alexandria, VA 22314, http:// d , d , . d = diameter values of the indentations in mm,
1 2 n
www.americanbearings.org.
and
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
n = number of indentations (see Annex A4).
4th Floor, New York, NY 10036, http://www.ansi.org.
E10 − 23
3.2.3 The repeatability R in the performance of a Brinell 5. Principles of Test and Apparatus
hardness machine at each hardness level, under the particular
5.1 Brinell Hardness Test Principle—The general principle
verification conditions, is estimated by the percent range of
of the Brinell indentation hardness test consists of two steps
diameter values of n indentations made on a standardized test
(see Fig. 1).
block as part of a performance verification, relative to the
5.1.1 Step 1—The indenter is brought into contact with the
¯
average of the n measured diameter values d (Eq 2), defined as:
test specimen in a direction perpendicular to the surface, and
the test force F is applied. The test force is held for a specified
d 2 d
max min
R 5 100 × (3)
dwell time and then removed.
¯
d
5.1.2 Step 2—The diameter of the indentation is measured
where:
in at least two directions perpendicular to each other. The
Brinell hardness value is derived from the mean of the diameter
d = diameter value of the largest measured indentation
max
measurements.
d = diameter value of the smallest measured indentation,
min
and
5.2 Brinell Testing Machine—Equipment for Brinell hard-
¯
= average of the diameter values of the n indentations.
d(Eq
ness testing usually consists of a testing machine, which
2)
supports the test specimen and applies an indenting force to a
¯ ball in contact with the specimen, and a system for measuring
3.2.4 The average H of a set of n Brinell hardness measurement
the mean diameter of the indentation in accordance with the
values H , H , ., H is calculated as:
1 2 n
Brinell hardness test principle. The design of the testing
H 1H 1…1H
1 2 n
¯
machine shall be such that no rocking or lateral movement of
H 5 (4)
n
the indenter or specimen occurs while the force is being
applied. The design of the testing machine shall ensure that the
3.2.5 The error E in the performance of a Brinell hardness
force to the indenter is applied smoothly and without impact
machine at each hardness level, under the particular verifica-
forces. Precautions shall be taken to prevent a momentary high
tion conditions, is estimated by the percent error of the average
test force caused by the inertia of the system, hydraulic system
of n indentation measurements made on a standardized test
overshoot, etc.
block as part of a performance verification relative to the
5.2.1 See the Equipment Manufacturer’s Instruction Manual
certified average hardness value of the standardized test block,
for a description of the machine’s characteristics, limitations,
defined as:
and respective operating procedures.
¯
H 2 H
? STD?
5.2.2 Anvils—An anvil, or specimen support, should be used
E 5 100 ×S D (5)
H
STD
that is suitable for the specimen to be tested. The seating and
supporting surfaces of all anvils should be clean and free of
where:
foreign material. Typically, anvils need only be replaced if they
¯
H (Eq 4) = average of n hardness tests H , H , ., H made
1 2 n
fail to support the test surface perpendicular to the indenter, or
on a standardized test block as part of a perfor-
they are deemed unsafe.
mance verification,
5.2.3 Indenters—Indenters for the Brinell hardness test shall
H = certified average hardness value of the standard-
STD
be tungsten carbide balls of four allowed diameters (1, 2.5, 5
ized test block, and
and 10 mm). Indenters shall meet the requirements defined in
¯
= absolute value (non-negative value without re-
|H2H |
STD
¯ Annex A3.
gard to its sign) of the difference between H and
5.2.4 Oil, dirt, or other foreign materials shall not be
H .
STD
allowed to accumulate on the indenter, as this will affect the
test results.
4. Significance and Use
4.1 The Brinell hardness test is an indentation hardness test
that can provide useful information about metallic materials.
This information may correlate to tensile strength, wear
resistance, ductility, or other physical characteristics of metal-
lic materials, and may be useful in quality control and selection
of materials.
4.2 Brinell hardness tests are considered satisfactory for
acceptance testing of commercial shipments, and have been
used extensively in industry for this purpose.
4.3 Brinell hardness testing at a specific location on a part
may not represent the physical characteristics of the whole part
or end product. FIG. 1 Principle of Test
E10 − 23
TABLE 3 Test Conditions and Recommended Hardness Range
5.2.5 Measurement Device—The measurement device used
for the measurement of the diameter of Brinell indentations Ball Recommended
Nominal Value of
Brinell Force-
Diameter Hardness
Test Force, F
may be an integral part of the hardness machine or a separate
Hardness Diameter
D Range
A
Scale Ratio
stand-alone instrument. The allowable measurement devices
N kgf
mm HBW
are classified into two types. The Type A device includes
HBW 10/3000 10 30 29420 3000 95.5 to 650
HBW 10/1500 10 15 14710 1500 47.7 to 327
microscopes having movable measuring lines with some type
HBW 10/1000 10 10 9807 1000 31.8 to 218
of indicator or computerized measuring system, or an image
HBW 10/500 10 5 4903 500 15.9 to 109
analysis system. The Type B device is a hand-held microscope
HBW 10/250 10 2.5 2452 250 7.96 to 54.5
(usually 20× or 40×) with fixed measuring lines. HBW 10/125 10 1.25 1226 125 3.98 to 27.2
HBW 10/100 10 1 980.7 100 3.18 to 21.8
5.2.5.1 Type A Device—The acceptable minimum resolution
HBW 5/750 5 30 7355 750 95.5 to 650
for a Type A device shall be as given in Table 2.
HBW 5/250 5 10 2452 250 31.8 to 218
HBW 5/125 5 5 1226 125 15.9 to 109
5.2.5.2 Type B Device—The acceptable maximum spacing
HBW 5/62.5 5 2.5 612.9 62.5 7.96 to 54.5
between the graduated lines of Type B devices shall be as given
HBW 5/31.25 5 1.25 306.5 31.25 3.98 to 27.2
in Table 2. Type B devices shall not be used for measuring
HBW 5/25 5 1 245.2 25 3.18 to 21.8
HBW 2.5/ 2.5 30 1839 187.5 95.5 to 650
indentations made with 2.5 mm and 1 mm ball indenters.
187.5
5.3 Verification—Brinell testing machines and indentation
HBW 2.5/62.5 2.5 10 612.9 62.5 31.8 to 218
HBW 2.5/ 2.5 5 306.5 31.25 15.9 to 109
measurement devices shall be verified periodically in accor-
31.25
dance with Annex A1.
HBW 2.5/ 2.5 2.5 153.2 15.625 7.96 to 54.5
15.625
5.4 Test Blocks—Test blocks meeting the requirements of
HBW 2.5/ 2.5 1.25 76.61 7.8125 3.98 to 27.2
Annex A4 shall be used to verify the testing machine in
7.8125
HBW 2.5/6.25 2.5 1 61.29 6.25 3.18 to 21.8
accordance with Annex A1.
HBW 1/30 1 30 294.2 30 95.5 to 650
5.5 Brinell Hardness Scales—The combinations of indent-
HBW 1/10 1 10 98.07 10 31.8 to 218
HBW 1/5 1 5 49.03 5 15.9 to 109
ers and test forces define the Brinell hardness scales. The
HBW 1/2.5 1 2.5 24.52 2.5 7.96 to 54.5
standard Brinell hardness scales and test forces are given in
HBW 1/1.25 1 1.25 12.26 1.25 3.98 to 27.2
Table 3, corresponding to force-diameter ratios (see Table 1) of HBW 1/1 1 1 9.807 1 3.18 to 21.8
A
1, 1.25, 2.5, 5, 10 and 30. Brinell hardness values should be
See Table 1.
determined and reported in accordance with one of these
standard scales. Other scales using non-standard test forces
may be used by special agreement. Examples of other scales
5.6.1.3 The applied force dwell time, s, if other than 10 s to
and the corresponding force-diameter ratio (in parentheses) are
15 s.
HBW 10/750 (7.5), HBW 10/2000 (20), HBW 10/2500 (25),
5.6.2 The only exception to the above requirement is for the
HBW 5/187.5 (7.5), and HBW 5/500 (20).
HBW 10/3000 scale when a 10 s to 15 s dwell time is used.
Only in the case of this one Brinell hardness scale may the
5.6 Calculation of the Brinell Hardness Number—The
designation be reported simply as HBW.
Brinell hardness number shall be calculated from the mean
5.6.3 Examples:
diameter d of the indentation using Eq 1 or from the values
given in Appendix X1.
220 HBW = Brinell hardness of 220 determined with a ball of 10 mm diameter
and with a test force of 29.42 kN (3000 kgf) applied for 10 s to 15 s
5.6.1 Brinell hardness values shall not be designated by a
number alone because it is necessary to indicate which indenter
350 HBW 5/750 = Brinell hardness of 350 determined with a ball of 5 mm
and which force has been employed in making the test (see
diameter and with a test force of 7.355 kN (750 kgf) applied for 10 s to 15 s
Table 3). Brinell hardness numbers shall be followed by the
600 HBW 1/30/20 = Brinell hardness of 600 determined with a ball of 1 mm
symbol HBW, and be supplemented by an index indicating the
diameter and with a test force of 294.2 N (30 kgf) applied for 20 s
test conditions in the following order:
5.7 Use of Portable Brinell Hardness Testing Machines:
5.6.1.1 Diameter of the ball, mm,
5.7.1 A fixed-location Brinell hardness testing machine may
5.6.1.2 A value representing the test force, kgf, (see Table 3)
not be capable of testing certain samples because of the sample
and,
size or weight, sample location, accessibility of the test point or
other requirements. In these circumstances, the use of a
portable Brinell hardness testing machine is an acceptable
method to test these samples. This method allows the use of a
TABLE 2 Resolution and Graduation Spacing of Indentation
portable Brinell hardness testing machine as follows.
Measuring Devices
5.7.1.1 The portable Brinell hardness testing machine shall
Type A Type B
meet the requirements of this method, including the test
Minimum Maximum
Ball Diameter
principle, apparatus, indenters, applied forces, test procedures
Indicator Resolution Graduation Spacing
mm
mm mm and the direct and indirect verifications of the testing machine
10 0.0100 0.100 (except as indicated in Table A1.1). Test Method E110 covers
5 0.0050 0.050
portable Brinell hardness testing machines that cannot be
2.5 0.0025 –
directly verified or cannot pass direct verification, but meet the
1 0.0010 –
other requirements of this method.
E10 − 23
TABLE 4 Minimum Specimen Thickness Based on Ten-Times the
5.7.1.2 A portable Brinell hardness testing machine shall be
Indentation Depth
used only when testing circumstances make it impractical to
Minimum Specimen Thickness
use a fixed-location Brinell hardness testing machine. In such Diameter of
Indentation,
10 mm 5 mm 2.5 mm 1 mm
cases, it is recommended that an agreement or understanding
d
Ball Ball Ball Ball
be made between all parties involved (for example, testing
mm mm in. mm in. mm in. mm in.
service and customer) that a portable Brinell hardness testing
0.2 0.1 0.004
machine will be used instead of a fixed-location Brinell
0.3 0.2 0.009
hardness testing machine (see 5.7.1).
0.4 0.4 0.016
0.5 0.7 0.026
5.7.1.3 The portable Brinell hardness testing machine shall
0.6 0.4 0.014 1.0 0.039
measure hardness by the Brinell hardness test principle (see
0.7 0.5 0.020
5.1). Portable hardness testing machines or instruments that
0.8 0.7 0.026
0.9 0.8 0.033
measure hardness by other means or procedures different than
1.0 1.0 0.041
the Brinell hardness test principle, such as those defined in Test
1.1 1.3 0.050
Methods A833, A956/A956M, A1038 or B647, produce con- 1.2 0.7 0.029 1.5 0.060
1.3 0.9 0.034 1.8 0.072
verted Brinell hardness values and do not comply with this
1.4 1.0 0.039 2.1 0.084
method.
1.5 1.2 0.045 2.5 0.098
5.7.2 Daily Verification of portable hardness testing 1.6 1.3 0.052
1.7 1.5 0.059
machines—Portable hardness testing machines are susceptible
1.8 1.7 0.066
to damage when they are transported or carried from one test
1.9 1.9 0.074
site to another. Therefore, in addition to complying with the
2.0 2.1 0.082
2.2 2.6 0.100
daily verification requirements specified in 7.1 and Annex A1,
2.4 1.5 0.058 3.1 0.121
a daily verification shall be performed at each test worksite
2.6 1.7 0.068 3.6 0.144
where the hardness tests are to be made just prior to making the 2.8 2.0 0.079 4.3 0.169
3.0 2.3 0.091 5.0 0.197
hardness tests. The verification shall be performed with the
3.2 2.6 0.104
portable hardness testing machine oriented as closely as
3.4 3.0 0.117
practical to the position that it will be used. It is recommended 3.6 3.4 0.132
3.8 3.8 0.148
that the daily verification be repeated occasionally during
4.0 4.2 0.164
testing and after testing is completed.
4.2 4.6 0.182
4.4 5.1 0.201
5.7.3 Additional reporting requirements, when using a por-
4.6 5.6 0.221
table Brinell hardness testing machine, are given in 9.2.
4.8 6.1 0.242
5.7.4 Portable hardness testing machines by the nature of
5.0 6.7 0.264
their application may induce errors that could influence the test 5.2 7.3 0.287
5.4 7.9 0.312
results. To understand the differences in results expected
5.6 8.6 0.338
between portable and fixed-location Brinell hardness testing
5.8 9.3 0.365
machines, the user should compare the results of the precision
and bias studies given in Section 10 and in Test Method E110.
polished flat with abrasive material so that the edge of the
6. Test Piece
indentation can be clearly defined to permit the measurement
6.1 There is no standard shape or size for a Brinell test of the diameter to the specified accuracy. Preparation shall be
specimen. The test piece on which the indentation is made
carried out in such a way that any alteration of the surface
should conform to the following: hardness of the test surface (for example, due to overheating or
6.1.1 Thickness—The thickness of the specimen tested shall
cold-working) is minimized.
be such that no bulge or other marking showing the effect of
7. Test Procedure
the test force appears on the side of the piece opposite the
indentation. The thickness of the material under test should be
7.1 The diameter of the indentation should be between 24 %
at least ten times the depth of the indentation h (see Table 4).
and 60 % of the ball diameter. Approximate Brinell hardness
Table 4 can also be used as a guideline for the minimum depth
numbers are given in Table 3 for the above range of indentation
of a layer of a material, such as a coating.
diameters.
NOTE 1—Brinell hardness testing can use high test forces. Under certain
NOTE 2—A lower limit in indentation diameter is recommended
conditions of testing a relatively thin material or coating on a material with
because of the risk in damaging the ball and the difficulty in measuring the
high hardness, there is a potential for the test material to break or shatter
indentation. The upper limit is recommended because of a reduction in
under load resulting in serious personal injury or damage to equipment.
sensitivity as the diameter of the indentation approaches the ball diameter.
Users are strongly cautioned to exercise extreme care when testing a
The thickness and spacing requirements may determine the maximum
material that could potentially fail under load. If there is a concern or
permissible diameter of indentation for a specific test.
doubt, do not test the material.
NOTE 3—It is not mandatory that Brinell tests conform to the hardness
scales of Table 3. It should be realized that different Brinell hardness
6.1.2 Width—The minimum width shall conform to the
numbers may be obtained for a given material by using different forces on
requirements for indentation spacing.
the same size of ball. For the purpose of obtaining a continuous scale of
6.1.3 Finish—When necessary, the surface on which the
values, it may be desirable to use a single force to cover the complete
indentation is to be made should be filed, ground, machined or range of hardness for a given class of materials.
E10 − 23
7.2 The Brinell hardness test is not recommended for arithmetic mean of the measurements shall be used for the
materials above 650 HBW 10/3000. calculation of the Brinell hardness number.
7.6.2 For routine testing, the diameter of the indentation
7.3 Direct comparisons of Brinell hardness numbers for
shall be measured to the resolution of the measuring device
tests using different scales can be made only if the force-
when using a Type A device, or one-half the graduation spacing
diameter ratio is maintained (see Table 3). Brinell hardness
when using a Type B device.
tests made on the same test material, but using different force-
7.6.3 For tests on flat surfaces, the difference between the
diameter ratios, will produce different Brinell hardness num-
largest and smallest measured diameters for the same indenta-
bers.
tion shall not exceed 1% of the indenter ball diameter unless it
7.3.1 Example—An HBW 10/500 test will usually approxi-
is specified in the product specification, such as for an
mate an HBW 5/125 test since the force-diameter ratio is 5 for
anisotropic grain structure.
both scales. However, a value of 160 HBW 10/500 will be
7.6.3.1 Example—For indentations made using ball indent-
approximately equal to 180 HBW 10/3000 on the same test
ers having 10 mm, 5 mm, 2.5 mm and 1 mm diameters, the
material because of different force-diameter ratios (5 and 30,
maximum differences between the largest and smallest mea-
respectively).
sured diameters are 0.1 mm, 0.05 mm, 0.025 mm and 0.01 mm,
7.4 Daily Verification—A daily verification of the testing
respectively.
machine shall be performed in accordance with Annex A1 prior
7.6.4 When indentations are made on a curved surface, the
to making hardness tests. Hardness measurements shall be
minimum radius of curvature of the surface shall be two and a
made only on the calibrated surface of the test block. It is also
half times the diameter of the ball. Indentations made on
recommended that the operation of the machine be checked in
curved surfaces may be slightly elliptical rather than circular in
accordance with the daily verification method specified in
shape. The measurements of the indentation shall be taken as
Annex A1 after each change of the test force, anvil or the
the mean of the major and minor axes.
indenter.
7.7 Indentation Spacing—The distance between the centers
7.5 Indentation Procedure—The Brinell hardness test shall
of two adjacent indentations shall be at least three times the
be carried out as follows:
diameter of the mean indentation.
7.5.1 Bring the indenter into contact with the test surface in
7.7.1 The distance from the center of any indentation to an
a direction perpendicular to the surface without shock, vibra-
edge of the test piece shall be at least two and a half times the
tion or overshoot. The angle between the indenter force-line
diameter of the mean indentation.
and the surface of the specimen should be perpendicular.
7.8 Brinell hardness tests should be carried out at an
7.5.2 Apply the test force F within 1 s to 8 s. Faster force
ambient temperature within the limits of 10 °C to 35 °C (50 °F
application times are permitted if it is demonstrated that test
to 95 °F). Users of the Brinell test are cautioned that the
results are not affected.
temperature of the test material and the temperature of the
7.5.3 Maintain the fully applied test force for 10 s to 15 s,
hardness tester may affect the test results. Consequently, users
with the following exception.
should ensure that the test temperature does not adversely
7.5.3.1 In the case of materials exhibiting excessive plastic
flow after application of the test force, special considerations affect the hardness measurement.
may be necessary since the indenter will continue to penetrate
into the material. Testing of these materials may require the use 8. Conversion to Other Hardness Scales or Tensile
Strength Values
of a longer applied force dwell time than stated above, which
should be specified in the product specification. When an
8.1 There is no general method of accurately converting the
extended applied force dwell time is used, the dwell time shall
Brinell hardness numbers on one scale to Brinell hardness
be recorded and reported with the test results (see 5.6.1).
numbers on another scale, or to other types of hardness
7.5.4 At the end of the dwell time, immediately remove the
numbers, or to tensile strength values. Such conversions are, at
test force without shock or vibration.
best, approximations and, therefore should be avoided except
7.6 Measurement of Indentation: for special cases where a reliable basis for the approximate
7.6.1 Measure the diameter of each indentation in two conversion has been obtained by comparison tests. Additional
directions, perpendicular (90°) to each other. Additional mea- requirements are specified in 9.3 and 9.4 when reporting
surements of the indentation diameter may also be made. The converted hardness values.
TABLE 5 Summary of Statistical Information
¯ ¯
Test Block X SX Sr SR r R
PB PB
100 HBW 5/500 101.71 2.31 0.91 2.42 2.56 6.78
170 HBW 10/1500 175.42 2.08 0.89 2.21 2.49 6.18
225 HBW 10/1500 221.83 4.00 2.20 4.38 6.16 12.28
300 HBW 10/1500 284.63 5.48 2.64 5.89 7.39 16.48
500 HBW 10/3000 502.21 11.78 4.74 12.40 13.28 34.71
300 HBW 10/3000 291.25 6.72 2.08 6.93 5.83 19.42
200 HBW 10/3000 197.71 5.64 4.47 6.72 12.51 18.80
E10 − 23
NOTE 4—The Standard Hardness Conversion Tables for Metals, E140,
9.3.2 Other formats for reporting converted hardness values,
give approximate conversion values for specific materials such as steel,
such as data tables, may be used, however, the original
austenitic stainless steel, nickel and high-nickel alloys, cartridge brass,
measurement number and test scale shall also be reported and
copper alloys, and alloyed white cast irons.
clearly identified.
9. Report
9.4 Since all converted hardness values are considered
9.1 At a minimum, the test report shall include the following approximate, the reported hardness values shall be rounded in
accordance with the Rounding Method of Practice E29 and
information:
¯
should have no more significant digits than is given for the data
9.1.1 The Brinell hardness value H of the test results
in the applicable conversion or correction table.
rounded to three significant digits, including all zero digits, in
accordance with Practice E29, for example, 225 HBW, 100
10. Precision and Bias
HBW 10/500, 95.9 HBW or 9.10 HBW 5/62.5.
10.1 The precision of this test method is based on an
9.1.2 The test conditions, when other than a 3000 kgf (29.42
interlaboratory study of Test Method E10 conducted in 2006.
kN) applied force, a 10 mm ball diameter, and a 10 s to 15 s
This replaces a previous study which used steel ball indenters.
application of test force are used (see 5.6.1).
Each of eight laboratories tested the Brinell hardness of
9.1.3 A statement that the indentation measuring device was
metallic materials. Three analyses were performed on a total of
Type A, when such a device is used. When a Type B
seven different materials of varying levels of hardness. Three
indentation measuring device is used, no statement is required.
replicates of each analysis were performed. The results from
9.1.4 The ambient temperature of the test, if outside the 5
this study are filed in an ASTM Research Report.
limits of 10 °C to 35 °C (50 °F to 95 °F), unless it has been
10.2 Repeatability—Two test results obtained within one
shown to not affect the measurement result.
laboratory shall be judged not equivalent if they differ by more
9.2 Reporting Portable Testing Machine Hardness Values—
than the r value for that material; r is the interval
PB PB
When using a portable Brinell hardness testing machine, the
representing the critical difference between two test results for
measured hardness number shall be reported in accordance
the same material, obtained by the same operator using the
with 9.1, and appended with a /P to indicate that it was
same equipment on the same day in the same laboratory.
determined by a portable Brinell hardness testing machine. For
10.3 Reproducibility—Two test results should be judged not
example:
equivalent if they differ by more than the R value for that
PB
220 HBW/P 10/3000 = Brinell hardness of 220 determined
material; R is the interval representing the difference be-
PB
with a tungsten carbide ball of 10 mm diameter and with a test
tween two test results for the same material, obtained by
force of 3000 kgf (29.42 kN) applied for 10 s to 15 s.
different operators using different equipment in different labo-
350 HBW/P 5/750 = Brinell hardness of 350 determined with
ratories.
a ball of 5 mm diameter and with a test force of 750 kgf (7.355
kN) applied for 10 s to 15 s. 10.4 Any judgment in accordance with statements 10.2 or
600 HBW/P 2.5/62.5/20 = Brinell hardness of 600 determined
10.3 would have an approximate 95 % probability of being
with a ball of 2.5 mm diameter and with a test force of 62.5 kgf correct.
(612.9 N) applied for 20 s.
10.5 Results from the interlaboratory study are summarized
9.3 Reporting Converted Hardness Values—When reporting in Table 5.
hardness values that have been converted from one type of
10.6 Bias—At the time of the study, there was no accepted
hardness test or hardness scale to another type of hardness test
reference material suitable for determining the bias for this test
or hardness scale, the original measurement number and test
method, therefore no statement on bias can be made.
scale shall also be reported (see E140).
11. Keywords
9.3.1 A common historical practice is to report the con-
verted hardness value followed by the measured hardness value
11.1 Brinell; hardness; mechanical test; metals
given in parentheses. For example: 372 HV (353 HBW), where
372 HV is the converted hardness value and 353 HBW is the 5
Supporting data have been filed at ASTM International Headquarters and may
original measurement value. be obtained by requesting Research Report RR:E28-1023.
E10 − 23
ANNEXES
(Mandatory Information)
A1. VERIFICATION OF BRINELL HARDNESS TESTING MACHINES
A1.1 Scope A1.2.4 Indirect verification of the testing machine shall be
performed at the location where it will be used.
A1.1.1 Annex A1 specifies three types of procedures for
verifying Brinell hardness testing machines: direct verification, A1.2.5 Direct verification of newly manufactured or rebuilt
indirect verification, and daily verification. testing machines may be performed at the place of
manufacture, rebuild, repair or the location of use.
A1.1.2 Direct verification is a process for verifying that
NOTE A1.1—It is recommended that the calibration agency that is used
critical components of the hardness testing machine are within
to conduct the verifications of Brinell hardness testing machines be
allowable tolerances by directly measuring the test forces,
accredited to the requirements of ISO 17025 (or an equivalent) by an
indentation measuring system, and testing cycle.
accrediting body recognized by the International Laboratory Accreditation
Cooperation (ILAC) as operating to the requirements of ISO/IEC 17011.
A1.1.3 Indirect verification is a process for periodically
verifying the performance of the testing machine by means of
A1.3 Direct Verification
standardized test blocks and indenters.
A1.3.1 A direct verification of the testing machine shall be
A1.1.4 The daily verification is a process for monitoring the
performed at specific instances in accordance with Table A1.1.
performance of the testing machine between indirect verifica-
The test forces, indentation measuring system and testing cycle
tions by means of standardized test blocks.
shall be verified as follows.
NOTE A1.2—Direct verification is a useful tool for determining the
A1.2 General Requirements
sources of error in a Brinell hardness testing machine. It is recommended
that testing machines undergo direct verification periodically to make
A1.2.1 The testing machine shall be verified at specific
certain that errors in one component of the machine are not being offset by
instances and at periodic intervals as specified in Table A1.1,
errors in another component.
and when circumstances occur that may affect the performance
A1.3.2 Verification of the Test Forces—For each Brinell
of the testing machine.
scale that will be used, the corresponding test force shall be
A1.2.2 The temperature at the verification site shall be
measured. The test forces shall be measured by means of a
measured with an instrument having an accuracy of at least
Class A elastic force measuring instrument having an accuracy
62.0 °C or 63.6 °F. It is recommended that the temperature be
of at least 0.25 %, as described in Practice E74.
monitored throughout the verification period, and significant
A1.3.2.1 Make three measurements of each force. The
temperature variations be recorded and reported. The tempera-
forces shall be measured as they are applied during testing;
ture at the verification site does not need to be measured for a
however, longer dwell times are allowed when necessary to
daily verification.
enable the measuring device to obtain accurate measurements.
A1.2.3 All instruments used to make measurements re- A1.3.2.2 Each test force F shall be accurate to within 61 %
quired by this Annex shall be calibrated traceable to national of the nominal test force as defined in Table 3.
standards when a system of traceability exists, except as noted
A1.3.3 Verification of the Indentation Measuring System—
otherwise.
The measuring device used to determine the diameter of the
indentation shall be verified at five intervals over the working
range by comparison with an accurate scale such as a stage
micrometer. The accuracy of the stage micrometer used to
TABLE A1.1 Verification Schedule for a Brinell Testing Machine
verify both Type A and Type B devices shall be at least 0.005
Verification
Schedule
Procedure mm for 5 mm and 10 mm ball tests and at least 0.001 mm for
Direct • When a testing machine is new, or when adjustments, 2.5 mm and 1 mm ball tests.
verification modifications or repairs are made that could affect the
A1.3.3.1 For Type A devices, the error between the stage
application of the test forces or the measuring system.
micrometer and the measuring device over each interval shall
• When a testing machine fails an indirect verification.
not exceed the Type A minimum indicator resolution shown in
Indirect • Recommended every 12 months, or more often if
Table 2 for the size of ball to be used.
verification needed.
A1.3.3.2 For Type B devices, it is not possible to determine
• Shall be no longer than every 18 months.
• When a test machine is installed or moved, only the
a quantitative error value. Position the measuring device such
procedure for verifying the as-found condition is required,
that the lines of the measuring device line-up with the lines of
(see A1.4.4). Indirect verification is not required after
the stage micrometer as closely as possible. If any lines of the
moving a portable or moveable Brinell hardness testing
machine (see 3.1.10, 3.1.11, and 5.7).
measuring device do not, at least partially, overlap the corre-
• Following a direct verification.
sponding lines of the stage micrometer, then the measuring
device shall be adjusted.
Daily • Required each day that hardness tests are made.
verification • Recommended whenever the indenter or test force is
A1.3.4 Verification of the Testing Cycle—The testing ma-
changed.
chine shall be verified to be capable of meeting the testing
E10 − 23
TABLE A1.2 Repeatability and Error of the Testing Machine
cycle tolerances specified in 7.5. Direct verification of the
testing cycle is to be verified by the testing machine manufac- Maximum Permissible
Reference Block Maximum Permissible
Repeatability, R
Hardness Error, E
turer at the time of manufacture, or when the testing machine
¯
HBW % of H
% of d
is returned to the manufacturer for repair, or when a problem
(See Eq 3) (See Eq 5)
with the testing cycle is suspected. Verification of the testing
HBW # 125 3 3
cycle is recommended but not required as part of the direct
125 < HBW # 225 2.5 3
verification at other times.
HBW > 225 2 3
A1.3.5 Direct Verification Failure—If any of the direct
verifications fail the specified requirements, the testing ma-
chine shall not be used until it is adjusted or repaired. If the test
forces, indentation measuring system or testing cycle may have
A1.4.6 Indirect Verification Procedure—The indirect verifi-
been affected by an adjustment or repair, the affected compo-
cation procedure is designed to verify that for all of the Brinell
nents shall be verified again by a direct verification.
hardness scales to be used, each test force is being accurately
applied, each indenter-ball size is correct, and the measuring
A1.4 Indirect Verification
device is calibrated correctly for the range of indentation sizes
A1.4.1 An indirect verification of the testing machine shall
that these scales produce. This is accomplished by making
be performed in accordance with the schedule given in Table
Brinell hardness tests on test blocks that have been calibrated
A1.1 Indirect verifications may be required more frequently
for appropriate Brinell hardness scales that employ each of the
than stated in Table A1.1 and should be based on the usage of
corresponding test forces and indenter ball sizes.
the testing machine.
A1.4.6.1 The calibrated values and Brinell hardness scales
A1.4.2 The testing machine shall be verified for each test of the test blocks shall be chosen such that the following
force and for each ball diameter that will be used prior to the criteria are met:
next indirect verification. Hardness tests made using Brinell (1) For each test force that will be used, at least one block
scales that have not been verified within the schedule given in shall be tested.
Table A1.1 do not meet this standard. (2) For each indenter-ball size that will be used, at least two
blocks shall be tested, one from a low hardness level and one
A1.4.3 Standardized test blocks used for the indirect veri-
from a high hardness level. As best as practical, choose the low
fication shall meet the requirements of Annex A4. Hardness
and high hardness levels from the range of commercially
measurements shall be made only on the calibrated surface of
available test blocks. In cases where more than one of the
the test block.
Brinell hardness scales to be verified employs the same ball
NOTE A1.3—It is recognized that appropriate standardized test blocks
size, then the Brinell scale using the highest test force shall be
are not available for all geometric shapes, materials, or hardness ranges.
verified on a low hardness level block to produce the largest
A1.4.4 As-found Condition—It is recommended that the
indentation size, and the Brinell scale using the lowest test
as-found condition of the testing machine be assessed as part of
force shall be verified on a high hardness level block to
an indirect verification. This is important for documenting the
produce the smallest indentation size. The two extremes of
historical performance of the machine. This procedure should
indentation size will verify the capability of the measuring
be conducted by the verification agency prior to any cleaning,
device. The blocks need not be from scales of the same
maintenance, adjustments, or repairs.
force/diameter ratio.
A1.4.4.1 When the as-found condition of the testing ma-
(3) Each test block’s calibrated Brinell scale is one of the
chine is assessed, the assessment shall be made using the user’s
scales to be verified.
indenter ball that is normally used with the testing machine.
(4) In cases where a Brinell scale should be verified using
A1.4.4.2 One or more standardized test blocks in the range
a low level and high level test block, but test blocks are
of normal testing should be tested for each Brinell scale that
commercially available for only one hardness level, perform
will undergo indirect verification.
the indirect verification using the one block, and directly verif
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E10 − 18 E10 − 23 American Association State Highway
and Transportation Officials Standard
AASHTO No.: T70–86
Standard Test Method for
Brinell Hardness of Metallic Materials
This standard is issued under the fixed designation E10; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This test method covers the determination of the Brinell hardness of metallic materials by the Brinell indentation hardness
principle. This standard provides the requirements for a Brinell testing machine and the procedures for performing Brinell hardness
tests.
1.2 This test method includes requirements for the use of portable Brinell hardness testing machines that measure Brinell hardness
by the Brinell hardness test principle and can meet the requirements of this test method, including the direct and indirect
verifications of the testing machine. Portable Brinell hardness testing machines that cannot meet the direct verification
requirements and can only be verified by indirect verification requirements are covered in Test Method E110.
1.3 This standard includes additional requirements in the following annexes:
Verification of Brinell Hardness Testing Machines Annex A1
Brinell Hardness Standardizing Machines Annex A2
Standardization of Brinell Hardness Indenters Annex A3
Standardization of Brinell Hardness Test Blocks Annex A4
1.4 This standard includes nonmandatory information in the following appendixes that relates to the Brinell hardness test:
Table of Brinell Hardness Numbers Appendix X1
Examples of Procedures for Determining Appendix X2
Brinell Hardness Uncertainty
1.5 At the time the Brinell hardness test was developed, the force levels were specified in units of kilograms-force (kgf). Although
this standard specifies the unit of force in the International System of Units (SI) as the Newton (N), because of the historical
precedent and continued common usage of kgf units, force values in kgf units are provided for information and much of the
discussion in this standard refers to forces in kgf units.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
This test method is under the jurisdiction of ASTM Committee E28 on Mechanical Testing and is the direct responsibility of Subcommittee E28.06 on Indentation
Hardness Testing.
Current edition approved July 1, 2018July 1, 2023. Published August 2018August 2023. Originally approved in 1924. Last previous edition approved in 20172018 as
E10 – 17.E10 – 18. DOI: 10.1520/E0010-18.10.1520/E0010-23.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E10 − 23
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
A833 Test Method for Indentation Hardness of Metallic Materials by Comparison Hardness Testers
A956A956/A956M Test Method for Leeb Hardness Testing of Steel Products
A1038 Test Method for Portable Hardness Testing by the Ultrasonic Contact Impedance Method
B647 Test Method for Indentation Hardness of Aluminum Alloys by Means of a Webster Hardness Gage
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E74 Practices for Calibration and Verification for Force-Measuring Instruments
E110 Test Method for Rockwell and Brinell Hardness of Metallic Materials by Portable Hardness Testers
E140 Hardness Conversion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hardness,
Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb Hardness
E384 Test Method for Microindentation Hardness of Materials
2.2 American Bearings Manufacturer Association Standard:
ABMA 10-1989 Metal Balls
2.3 ISO Standards:
ISO/IEC 17011 Conformity Assessment—General Requirements for Accreditation Bodies Accrediting Conformity Assessment
Bodies
ISO/IEC 17025 General Requirements for the Competence of Calibration and Testing
3. Terminology and Equations
3.1 Definitions:
3.1.1 calibration—determination of the values of the significant parameters by comparison with values indicated by a reference
instrument or by a set of reference standards.
3.1.2 verification—checking or testing to assure conformance with the specification.
3.1.3 standardization—to bring in conformance with a known standard through verification or calibration.
3.1.4 Brinell hardness test—an indentation hardness test using a verified machine to force an indenter (tungsten carbide ball with
diameter D), under specified conditions, into the surface of the material under test. The diameter of the resulting indentation d is
measured after removal of the force.
3.1.5 Brinell hardness number—a number, which is proportional to the quotient obtained by dividing the test force by the curved
surface area of the indentation which is assumed to be spherical and of the diameter of the ball.
3.1.6 Brinell hardness scale—a designation that identifies the specific combination of ball diameter and applied force used to
perform the Brinell hardness test.
3.1.7 Brinell hardness testing machine—a Brinell hardness machine used for general testing purposes.
3.1.8 Brinell hardness standardizing machine—a Brinell hardness machine used for the standardization of Brinell hardness test
blocks. The standardizing machine differs from a regular Brinell hardness testing machine by having tighter tolerances on certain
parameters.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Bearing Manufacturers Association (ABMA), 2025 M Street, NW, Suite 800, Washington, DC 20036,1001 N. Fairfax Street, Suite 500
Alexandria, VA 22314, http://www.americanbearings.org.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
E10 − 23
3.1.9 force-diameter ratio—a number calculated as the ratio of the test force in kgf to the square of the indenter ball diameter in
mm (see Table 1).
3.1.10 portable Brinell hardness testing machine—a Brinell hardness testing machine that is designed to be transported, carried,
set up, and operated by the users, and that measures Brinell hardness by the Brinell hardness test principle.
3.1.11 movable Brinell hardness testing machine—a Brinell hardness testing machine that is designed to be moved to different
locations on a moveable frame, table or similar support that is integral to the testing machine (for example, securely fixed to a
rolling table), or a Brinell hardness testing machine that is designed to move into the testing position prior to a test, (for example,
securely fixed to a moving support arm), and has been previously verified to ensure that such moves will not affect the hardness
result.
3.2 Equations:
3.2.1 The Brinell hardness number is calculated as:
2F
kgf
HBW 5 (1)
2 2
~ = !
πD D 2 D 2 d
where:
F = test force in kgf,
kgf
D = diameter of the indenter ball in mm, and
TABLE 1 Symbols and Designations
Symbol Designation
D Diameter of the ball, mm
F Test force, N
F Test force, kgf
kgf
F 5 ×F
kgf
g
n
where g is the acceleration due to gravity.
n
g = 9.80665 N/kgf
n
d Diameter value of the indentation, mm
d 1 1d 2 1{1d N
s d s d s d
d 5
N
where d(1), d(2) . d(N) are the measured indentation
diameters in mm, and N is the number of diameter mea-
surements (typically 2).
h Depth of the indentation, mm
2 2
D 2 D 2d
œ
h 5
Force-
F
kgf
Diameter
D
ratio
HBW Brinell hardness
Test Force
Surface area of indentation
2F
kgf
2 2
π D sD 2 D 2d d
œ
E10 − 23
d = measured mean diameter of the indentation in mm (see Table 1).
¯
3.2.2 The average mean diameter d of a set of n indentations is calculated as:
d 1d 1…1d
1 2 n
¯
d 5 (2)
n
where:
d , d , . d = diameter values of the indentations in mm, and
1 2 n
n = number of indentations (see Annex A4).
3.2.3 The repeatability R in the performance of a Brinell hardness machine at each hardness level, under the particular verification
conditions, is estimated by the percent range of diameter values of n indentations made on a standardized test block as part of a
¯
performance verification, relative to the average of the n measured diameter values d (Eq 2), defined as:
d 2 d
max min
R 5 100 × (3)
¯
d
where:
d = diameter value of the largest measured indentation
max
d = diameter value of the smallest measured indentation, and
min
¯
= average of the diameter values of the n indentations.
d(Eq
2)
¯
3.2.4 The averageH of a set of n Brinell hardness measurement values H , H , ., H is calculated as:
1 2 n
H 1H 1…1H
1 2 n
¯
H 5 (4)
n
3.2.5 The error E in the performance of a Brinell hardness machine at each hardness level, under the particular verification
conditions, is estimated by the percent error of the average of n indentation measurements made on a standardized test block as
part of a performance verification relative to the certified average hardness value of the standardized test block, defined as:
¯
H 2 H
? STD?
E 5 100 ×S D (5)
H
STD
where:
H¯ (Eq = average of n hardness tests H , H , ., H made on a standardized test block as part of a performance verification,
1 2 n
4)
H = certified average hardness value of the standardized test block, and
STD
¯ ¯
=
|H2H | absolute value (non-negative value without regard to its sign) of the difference between H and H .
STD STD
4. Significance and Use
4.1 The Brinell hardness test is an indentation hardness test that can provide useful information about metallic materials. This
information may correlate to tensile strength, wear resistance, ductility, or other physical characteristics of metallic materials, and
may be useful in quality control and selection of materials.
4.2 Brinell hardness tests are considered satisfactory for acceptance testing of commercial shipments, and have been used
extensively in industry for this purpose.
4.3 Brinell hardness testing at a specific location on a part may not represent the physical characteristics of the whole part or end
product.
E10 − 23
5. Principles of Test and Apparatus
5.1 Brinell Hardness Test Principle—The general principle of the Brinell indentation hardness test consists of two steps (see Fig.
1).
5.1.1 Step 1—The indenter is brought into contact with the test specimen in a direction perpendicular to the surface, and the test
force F is applied. The test force is held for a specified dwell time and then removed.
5.1.2 Step 2—The diameter of the indentation is measured in at least two directions perpendicular to each other. The Brinell
hardness value is derived from the mean of the diameter measurements.
5.2 Brinell Testing Machine—Equipment for Brinell hardness testing usually consists of a testing machine, which supports the test
specimen and applies an indenting force to a ball in contact with the specimen, and a system for measuring the mean diameter of
the indentation in accordance with the Brinell hardness test principle. The design of the testing machine shall be such that no
rocking or lateral movement of the indenter or specimen occurs while the force is being applied. The design of the testing machine
shall ensure that the force to the indenter is applied smoothly and without impact forces. Precautions shall be taken to prevent a
momentary high test force caused by the inertia of the system, hydraulic system overshoot, etc.
5.2.1 See the Equipment Manufacturer’s Instruction Manual for a description of the machine’s characteristics, limitations, and
respective operating procedures.
5.2.2 Anvils—An anvil, or specimen support, should be used that is suitable for the specimen to be tested. The seating and
supporting surfaces of all anvils should be clean and free of foreign material. Typically, anvils need only be replaced if they fail
to support the test surface perpendicular to the indenter, or they are deemed unsafe.
5.2.3 Indenters—Indenters for the Brinell hardness test shall be tungsten carbide balls of four allowed diameters (1, 2.5, 5 and 10
mm). Indenters shall meet the requirements defined in Annex A3.
5.2.4 Oil, dirt, or other foreign materials shall not be allowed to accumulate on the indenter, as this will affect the test results.
5.2.5 Measurement Device—The measurement device used for the measurement of the diameter of Brinell indentations may be
an integral part of the hardness machine or a separate stand-alone instrument. The allowable measurement devices are classified
into two types. The Type A device includes microscopes having movable measuring lines with some type of indicator or
computerized measuring system, or an image analysis system. The Type B device is a hand-held microscope (usually 20× or 40×)
with fixed measuring lines.
5.2.5.1 Type A Device—The acceptable minimum resolution for a Type A device shall be as given in Table 2.
5.2.5.2 Type B Device—The acceptable maximum spacing between the graduated lines of Type B devices shall be as given in Table
2. Type B devices shall not be used for measuring indentations made with 2.5 mm and 1 mm ball indenters.
5.3 Verification—Brinell testing machines and indentation measurement devices shall be verified periodically in accordance with
Annex A1.
FIG. 1 Principle of Test
E10 − 23
TABLE 2 Resolution and Graduation Spacing of Indentation
Measuring Devices
Type A Type B
Minimum Maximum
Ball Diameter
Indicator Resolution Graduation Spacing
mm
mm mm
10 0.0100 0.100
5 0.0050 0.050
2.5 0.0025 –
1 0.0010 –
5.4 Test Blocks—Test blocks meeting the requirements of Annex A4 shall be used to verify the testing machine in accordance with
Annex A1.
5.5 Brinell Hardness Scales—The combinations of indenters and test forces define the Brinell hardness scales. The standard
Brinell hardness scales and test forces are given in Table 3, corresponding to force-diameter ratios (see Table 1) of 1, 1.25, 2.5,
5, 10 and 30. Brinell hardness values should be determined and reported in accordance with one of these standard scales. Other
scales using non-standard test forces may be used by special agreement. Examples of other scales and the corresponding
force-diameter ratio (in parentheses) are HBW 10/750 (7.5), HBW 10/2000 (20), HBW 10/2500 (25), HBW 5/187.5 (7.5), and
HBW 5/500 (20).
5.6 Calculation of the Brinell Hardness Number—The Brinell hardness number shall be calculated from the mean diameter d of
the indentation using Eq 1 or from the values given in Appendix X1.
5.6.1 Brinell hardness values shall not be designated by a number alone because it is necessary to indicate which indenter and
which force has been employed in making the test (see Table 3). Brinell hardness numbers shall be followed by the symbol HBW,
and be supplemented by an index indicating the test conditions in the following order:
TABLE 3 Test Conditions and Recommended Hardness Range
Ball Recommended
Nominal Value of
Brinell Force-
Diameter Hardness
Test Force, F
Hardness Diameter
D Range
A
Scale Ratio
N kgf
mm HBW
HBW 10/3000 10 30 29420 3000 95.5 to 650
HBW 10/1500 10 15 14710 1500 47.7 to 327
HBW 10/1000 10 10 9807 1000 31.8 to 218
HBW 10/500 10 5 4903 500 15.9 to 109
HBW 10/250 10 2.5 2452 250 7.96 to 54.5
HBW 10/125 10 1.25 1226 125 3.98 to 27.2
HBW 10/100 10 1 980.7 100 3.18 to 21.8
HBW 5/750 5 30 7355 750 95.5 to 650
HBW 5/250 5 10 2452 250 31.8 to 218
HBW 5/125 5 5 1226 125 15.9 to 109
HBW 5/62.5 5 2.5 612.9 62.5 7.96 to 54.5
HBW 5/31.25 5 1.25 306.5 31.25 3.98 to 27.2
HBW 5/25 5 1 245.2 25 3.18 to 21.8
HBW 2.5/ 2.5 30 1839 187.5 95.5 to 650
187.5
HBW 2.5/62.5 2.5 10 612.9 62.5 31.8 to 218
HBW 2.5/ 2.5 5 306.5 31.25 15.9 to 109
31.25
HBW 2.5/ 2.5 2.5 153.2 15.625 7.96 to 54.5
15.625
HBW 2.5/ 2.5 1.25 76.61 7.8125 3.98 to 27.2
7.8125
HBW 2.5/6.25 2.5 1 61.29 6.25 3.18 to 21.8
HBW 1/30 1 30 294.2 30 95.5 to 650
HBW 1/10 1 10 98.07 10 31.8 to 218
HBW 1/5 1 5 49.03 5 15.9 to 109
HBW 1/2.5 1 2.5 24.52 2.5 7.96 to 54.5
HBW 1/1.25 1 1.25 12.26 1.25 3.98 to 27.2
HBW 1/1 1 1 9.807 1 3.18 to 21.8
A
See Table 1.
E10 − 23
5.6.1.1 Diameter of the ball, mm,
5.6.1.2 A value representing the test force, kgf, (see Table 3) and,
5.6.1.3 The applied force dwell time, s, if other than 10 s to 15 s.
5.6.2 The only exception to the above requirement is for the HBW 10/3000 scale when a 10 s to 15 s dwell time is used. Only
in the case of this one Brinell hardness scale may the designation be reported simply as HBW.
5.6.3 Examples:
220 HBW = Brinell hardness of 220 determined with a ball of 10 mm diameter
and with a test force of 29.42 kN (3000 kgf) applied for 10 s to 15 s
350 HBW 5/750 = Brinell hardness of 350 determined with a ball of 5 mm
diameter and with a test force of 7.355 kN (750 kgf) applied for 10 s to 15 s
600 HBW 1/30/20 = Brinell hardness of 600 determined with a ball of 1 mm
diameter and with a test force of 294.2 N (30 kgf) applied for 20 s
5.7 Use of Portable Brinell Hardness Testing Machines:
5.7.1 A fixed-location Brinell hardness testing machine may not be capable of testing certain samples because of the sample size
or weight, sample location, accessibility of the test point or other requirements. In these circumstances, the use of a portable Brinell
hardness testing machine is an acceptable method to test these samples. This method allows the use of a portable Brinell hardness
testing machine as follows.
5.7.1.1 The portable Brinell hardness testing machine shall meet the requirements of this method, including the test principle,
apparatus, indenters, applied forces, test procedures and the direct and indirect verifications of the testing machine (except as
indicated in Table A1.1). Test Method E110 covers portable Brinell hardness testing machines that cannot be directly verified or
cannot pass direct verification, but meet the other requirements of this method.
5.7.1.2 A portable Brinell hardness testing machine shall be used only when testing circumstances make it impractical to use a
fixed-location Brinell hardness testing machine. In such cases, it is recommended that an agreement or understanding be made
between all parties involved (for example, testing service and customer) that a portable Brinell hardness testing machine will be
used instead of a fixed-location Brinell hardness testing machine (see 5.7.1).
5.7.1.3 The portable Brinell hardness testing machine shall measure hardness by the Brinell hardness test principle (see 5.1).
Portable hardness testing machines or instruments that measure hardness by other means or procedures different than the Brinell
hardness test principle, such as those defined in Test Methods A833, A956A956/A956M, A1038 or B647, produce converted
Brinell hardness values and do not comply with this method.
5.7.2 Daily Verification of portable hardness testing machines—Portable hardness testing machines are susceptible to damage
when they are transported or carried from one test site to another. Therefore, in addition to complying with the daily verification
requirements specified in 7.1 and Annex A1, a daily verification shall be performed at each test worksite where the hardness tests
are to be made just prior to making the hardness tests. The verification shall be performed with the portable hardness testing
machine oriented as closely as practical to the position that it will be used. It is recommended that the daily verification be repeated
occasionally during testing and after testing is completed.
5.7.3 Additional reporting requirements, when using a portable Brinell hardness testing machine, are given in 9.2.
5.7.4 Portable hardness testing machines by the nature of their application may induce errors that could influence the test results.
To understand the differences in results expected between portable and fixed-location Brinell hardness testing machines, the user
should compare the results of the precision and bias studies given in Section 10 and in Test Method E110.
6. Test Piece
6.1 There is no standard shape or size for a Brinell test specimen. The test piece on which the indentation is made should conform
to the following:
E10 − 23
6.1.1 Thickness—The thickness of the specimen tested shall be such that no bulge or other marking showing the effect of the test
force appears on the side of the piece opposite the indentation. The thickness of the material under test should be at least ten times
the depth of the indentation h (see Table 4). Table 4 can also be used as a guideline for the minimum depth of a layer of a material,
such as a coating.
NOTE 1—Brinell hardness testing can use high test forces. Under certain conditions of testing a relatively thin material or coating on a material with high
hardness, there is a potential for the test material to break or shatter under load resulting in serious personal injury or damage to equipment. Users are
strongly cautioned to exercise extreme care when testing a material that could potentially fail under load. If there is a concern or doubt, do not test the
material.
6.1.2 Width—The minimum width shall conform to the requirements for indentation spacing.
6.1.3 Finish—When necessary, the surface on which the indentation is to be made should be filed, ground, machined or polished
flat with abrasive material so that the edge of the indentation can be clearly defined to permit the measurement of the diameter to
the specified accuracy. Preparation shall be carried out in such a way that any alteration of the surface hardness of the test surface
(for example, due to overheating or cold-working) is minimized.
7. Test Procedure
7.1 The diameter of the indentation should be between 2424 % and 60 % of the ball diameter. Approximate Brinell hardness
numbers are given in Table 3 for the above range of indentation diameters.
TABLE 4 Minimum Specimen Thickness Based on Ten-Times the
Indentation Depth
Minimum Specimen Thickness
Diameter of
Indentation,
10 mm 5 mm 2.5 mm 1 mm
d
Ball Ball Ball Ball
mm mm in. mm in. mm in. mm in.
0.2 0.1 0.004
0.3 0.2 0.009
0.4 0.4 0.016
0.5 0.7 0.026
0.6 0.4 0.014 1.0 0.039
0.7 0.5 0.020
0.8 0.7 0.026
0.9 0.8 0.033
1.0 1.0 0.041
1.1 1.3 0.050
1.2 0.7 0.029 1.5 0.060
1.3 0.9 0.034 1.8 0.072
1.4 1.0 0.039 2.1 0.084
1.5 1.2 0.045 2.5 0.098
1.6 1.3 0.052
1.7 1.5 0.059
1.8 1.7 0.066
1.9 1.9 0.074
2.0 2.1 0.082
2.2 2.6 0.100
2.4 1.5 0.058 3.1 0.121
2.6 1.7 0.068 3.6 0.144
2.8 2.0 0.079 4.3 0.169
3.0 2.3 0.091 5.0 0.197
3.2 2.6 0.104
3.4 3.0 0.117
3.6 3.4 0.132
3.8 3.8 0.148
4.0 4.2 0.164
4.2 4.6 0.182
4.4 5.1 0.201
4.6 5.6 0.221
4.8 6.1 0.242
5.0 6.7 0.264
5.2 7.3 0.287
5.4 7.9 0.312
5.6 8.6 0.338
5.8 9.3 0.365
E10 − 23
NOTE 2—A lower limit in indentation diameter is recommended because of the risk in damaging the ball and the difficulty in measuring the indentation.
The upper limit is recommended because of a reduction in sensitivity as the diameter of the indentation approaches the ball diameter. The thickness and
spacing requirements may determine the maximum permissible diameter of indentation for a specific test.
NOTE 3—It is not mandatory that Brinell tests conform to the hardness scales of Table 3. It should be realized that different Brinell hardness numbers
may be obtained for a given material by using different forces on the same size of ball. For the purpose of obtaining a continuous scale of values, it may
be desirable to use a single force to cover the complete range of hardness for a given class of materials.
7.2 The Brinell hardness test is not recommended for materials above 650 HBW 10/3000.
7.3 Direct comparisons of Brinell hardness numbers for tests using different scales can be made only if the force- diameter ratio
is maintained (see Table 3). Brinell hardness tests made on the same test material, but using different force- diameter ratios, will
produce different Brinell hardness numbers.
7.3.1 Example—An HBW 10/500 test will usually approximate an HBW 5/125 test since the force-diameter ratio is 5 for both
scales. However, a value of 160 HBW 10/500 will be approximately equal to 180 HBW 10/3000 on the same test material because
of different force-diameter ratios (5 and 30, respectively).
7.4 Daily Verification—A daily verification of the testing machine shall be performed in accordance with Annex A1 prior to
making hardness tests. Hardness measurements shall be made only on the calibrated surface of the test block. It is also
recommended that the operation of the machine be checked in accordance with the daily verification method specified in Annex
A1 after each change of the test force, anvil or the indenter.
7.5 Indentation Procedure—The Brinell hardness test shall be carried out as follows:
7.5.1 Bring the indenter into contact with the test surface in a direction perpendicular to the surface without shock, vibration or
overshoot. The angle between the indenter force-line and the surface of the specimen should be perpendicular.
7.5.2 Apply the test force F within 1 s to 8 s. Faster force application times are permitted if it is demonstrated that test results are
not affected.
7.5.3 Maintain the fully applied test force for 10 s to 15 s, with the following exception.
7.5.3.1 In the case of materials exhibiting excessive plastic flow after application of the test force, special considerations may be
necessary since the indenter will continue to penetrate into the material. Testing of these materials may require the use of a longer
applied force dwell time than stated above, which should be specified in the product specification. When an extended applied force
dwell time is used, the dwell time shall be recorded and reported with the test results (see 5.6.1).
7.5.4 At the end of the dwell time, immediately remove the test force without shock or vibration.
7.6 Measurement of Indentation:
7.6.1 Measure the diameter of each indentation in two directions, perpendicular (90°) to each other. Additional measurements of
the indentation diameter may also be made. The arithmetic mean of the measurements shall be used for the calculation of the
Brinell hardness number.
7.6.2 For routine testing, the diameter of the indentation shall be measured to the resolution of the measuring device when using
a Type A device, or one-half the graduation spacing when using a Type B device.
7.6.3 For tests on flat surfaces, the difference between the largest and smallest measured diameters for the same indentation shall
not exceed 1% of the indenter ball diameter unless it is specified in the product specification, such as for an anisotropic grain
structure.
7.6.3.1 Example—For indentations made using ball indenters having 10 mm, 5 mm, 2.5 mm and 1 mm diameters, the maximum
differences between the largest and smallest measured diameters are 0.1 mm, 0.05 mm, 0.025 mm and 0.01 mm, respectively.
E10 − 23
7.6.4 When indentations are made on a curved surface, the minimum radius of curvature of the surface shall be two and a half
times the diameter of the ball. Indentations made on curved surfaces may be slightly elliptical rather than circular in shape. The
measurements of the indentation shall be taken as the mean of the major and minor axes.
7.7 Indentation Spacing—The distance between the centers of two adjacent indentations shall be at least three times the diameter
of the mean indentation.
7.7.1 The distance from the center of any indentation to an edge of the test piece shall be at least two and a half times the diameter
of the mean indentation.
7.8 Brinell hardness tests should be carried out at an ambient temperature within the limits of 1010 °C to 35 °C (50(50 °F to
95 °F). Users of the Brinell test are cautioned that the temperature of the test material and the temperature of the hardness tester
may affect the test results. Consequently, users should ensure that the test temperature does not adversely affect the hardness
measurement.
8. Conversion to Other Hardness Scales or Tensile Strength Values
8.1 There is no general method of accurately converting the Brinell hardness numbers on one scale to Brinell hardness numbers
on another scale, or to other types of hardness numbers, or to tensile strength values. Such conversions are, at best, approximations
and, therefore should be avoided except for special cases where a reliable basis for the approximate conversion has been obtained
by comparison tests. Additional requirements are specified in 9.3 and 9.4 when reporting converted hardness values.
NOTE 4—The Standard Hardness Conversion Tables for Metals, E140, give approximate conversion values for specific materials such as steel, austenitic
stainless steel, nickel and high-nickel alloys, cartridge brass, copper alloys, and alloyed white cast irons.
9. Report
9.1 At a minimum, the test report shall include the following information:
¯
9.1.1 The Brinell hardness value H of the test results rounded to three significant digits, including all zero digits, in accordance
with Practice E29, for example, 225 HBW, 100 HBW 10/500, 95.9 HBW or 9.10 HBW 5/62.5.
9.1.2 The test conditions, when other than a 3000 kgf (29.42 kN) applied force, a 10 mm ball diameter, and a 10 s to 15 s
application of test force are used (see 5.6.1).
9.1.3 A statement that the indentation measuring device was Type A, when such a device is used. When a Type B indentation
measuring device is used, no statement is required.
9.1.4 The ambient temperature of the test, if outside the limits of 1010 °C to 35 °C (50(50 °F to 95 °F), unless it has been shown
to not affect the measurement result.
9.2 Reporting Portable Testing Machine Hardness Values—When using a portable Brinell hardness testing machine, the measured
hardness number shall be reported in accordance with 9.1, and appended with a /P to indicate that it was determined by a portable
Brinell hardness testing machine. For example:
220 HBW/P 10/3000 = Brinell hardness of 220 determined with a tungsten carbide ball of 10 mm diameter and with a test force
of 3000 kgf (29.42 kN) applied for 10 s to 15 s.
350 HBW/P 5/750 = Brinell hardness of 350 determined with a ball of 5 mm diameter and with a test force of 750 kgf (7.355 kN)
TABLE 5 Summary of Statistical Information
¯ ¯
Test Block Sr SR r R
X SX PB PB
100 HBW 5/500 101.71 2.31 0.91 2.42 2.56 6.78
170 HBW 10/1500 175.42 2.08 0.89 2.21 2.49 6.18
225 HBW 10/1500 221.83 4.00 2.20 4.38 6.16 12.28
300 HBW 10/1500 284.63 5.48 2.64 5.89 7.39 16.48
500 HBW 10/3000 502.21 11.78 4.74 12.40 13.28 34.71
300 HBW 10/3000 291.25 6.72 2.08 6.93 5.83 19.42
200 HBW 10/3000 197.71 5.64 4.47 6.72 12.51 18.80
E10 − 23
applied for 10 s to 15 s.
600 HBW/P 2.5/62.5/20 = Brinell hardness of 600 determined with a ball of 2.5 mm diameter and with a test force of 62.5 kgf
(612.9 N) applied for 20 s.
9.3 Reporting Converted Hardness Values—When reporting hardness values that have been converted from one type of hardness
test or hardness scale to another type of hardness test or hardness scale, the original measurement number and test scale shall also
be reported (see E140).
9.3.1 A common historical practice is to report the converted hardness value followed by the measured hardness value given in
parentheses. For example: 372 HV (353 HBW), where 372 HV is the converted hardness value and 353 HBW is the original
measurement value.
9.3.2 Other formats for reporting converted hardness values, such as data tables, may be used, however, the original measurement
number and test scale shall also be reported and clearly identified.
9.4 Since all converted hardness values are considered approximate, the reported hardness values shall be rounded in accordance
with the Rounding Method of Practice E29 and should have no more significant digits than is given for the data in the applicable
conversion or correction table.
10. Precision and Bias
10.1 The precision of this test method is based on an interlaboratory study of Test Method E10 conducted in 2006. This replaces
a previous study which used steel ball indenters. Each of eight laboratories tested the Brinell hardness of metallic materials. Three
analyses were performed on a total of seven different materials of varying levels of hardness. Three replicates of each analysis were
performed. The results from this study are filed in an ASTM Research Report.
10.2 Repeatability—Two test results obtained within one laboratory shall be judged not equivalent if they differ by more than the
r value for that material; r is the interval representing the critical difference between two test results for the same material,
PB PB
obtained by the same operator using the same equipment on the same day in the same laboratory.
10.3 Reproducibility—Two test results should be judged not equivalent if they differ by more than the R value for that material;
PB
R is the interval representing the difference between two test results for the same material, obtained by different operators using
PB
different equipment in different laboratories.
10.4 Any judgment in accordance with statements 10.2 or 10.3 would have an approximate 95 % probability of being correct.
10.5 Results from the interlaboratory study are summarized in Table 5.
10.6 Bias—At the time of the study, there was no accepted reference material suitable for determining the bias for this test method,
therefore no statement on bias can be made.
11. Keywords
11.1 Brinell; hardness; mechanical test; metals
Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:E28-1023.
E10 − 23
ANNEXES
(Mandatory Information)
A1. VERIFICATION OF BRINELL HARDNESS TESTING MACHINES
A1.1 Scope
A1.1.1 Annex A1 specifies three types of procedures for verifying Brinell hardness testing machines: direct verification, indirect
verification, and daily verification.
A1.1.2 Direct verification is a process for verifying that critical components of the hardness testing machine are within allowable
tolerances by directly measuring the test forces, indentation measuring system, and testing cycle.
A1.1.3 Indirect verification is a process for periodically verifying the performance of the testing machine by means of standardized
test blocks and indenters.
A1.1.4 The daily verification is a process for monitoring the performance of the testing machine between indirect verifications by
means of standardized test blocks.
A1.2 General Requirements
A1.2.1 The testing machine shall be verified at specific instances and at periodic intervals as specified in Table A1.1, and when
circumstances occur that may affect the performance of the testing machine.
A1.2.2 The temperature at the verification site shall be measured with an instrument having an accuracy of at least 62.0 °C or
63.6 °F. It is recommended that the temperature be monitored throughout the verification period, and significant temperature
variations be recorded and reported. The temperature at the verification site does not need to be measured for a daily verification.
TABLE A1.1 Verification Schedule for a Brinell Testing Machine
Verification
Schedule
Procedure
Direct • When a testing machine is new, or when adjustments,
verification modifications or repairs are made that could affect the
application of the test forces or the measuring system.
• When a testing machine fails an indirect verification.
Indirect • Recommended every 12 months, or more often if
verification needed.
• Shall be no longer than every 18 months.
• When a test machine is installed or moved, only the
procedure for verifying the as-found condition is required,
(see A1.4.4). Indirect verification is not required after
moving a portable or moveable Brinell hardness testing
machine (see 3.1.10, 3.1.11, and 5.7).
• Following a direct verification.
Daily • Required each day that hardness tests are made.
verification • Recommended whenever the indenter or test force is
changed.
E10 − 23
A1.2.3 All instruments used to make measurements required by this Annex shall be calibrated traceable to national standards when
a system of traceability exists, except as noted otherwise.
A1.2.4 Indirect verification of the testing machine shall be performed at the location where it will be used.
A1.2.5 Direct verification of newly manufactured or rebuilt testing machines may be performed at the place of manufacture,
rebuild, repair or the location of use.
NOTE A1.1—It is recommended that the calibration agency that is used to conduct the verifications of Brinell hardness testing machines be accredited
to the requirements of ISO 17025 (or an equivalent) by an accrediting body recognized by the International Laboratory Accreditation Cooperation (ILAC)
as operating to the requirements of ISO/IEC 17011.
A1.3 Direct Verification
A1.3.1 A direct verification of the testing machine shall be performed at specific instances in accordance with Table A1.1. The
test forces, indentation measuring system and testing cycle shall be verified as follows.
NOTE A1.2—Direct verification is a useful tool for determining the sources of error in a Brinell hardness testing machine. It is recommended that testing
machines undergo direct verification periodically to make certain that errors in one component of the machine are not being offset by errors in another
component.
A1.3.2 Verification of the Test Forces—For each Brinell scale that will be used, the corresponding test force shall be measured.
The test forces shall be measured by means of a Class A elastic force measuring instrument having an accuracy of at least 0.25 %,
as described in Practice E74.
A1.3.2.1 Make three measurements of each force. The forces shall be measured as they are applied during testing; however, longer
dwell times are allowed when necessary to enable the measuring device to obtain accurate measurements.
A1.3.2.2 Each test force F shall be accurate to within 61 % of the nominal test force as defined in Table 3.
A1.3.3 Verification of the Indentation Measuring System—The measuring device used to determine the diameter of the indentation
shall be verified at five intervals over the working range by comparison with an accurate scale such as a stage micrometer. The
accuracy of the stage micrometer used to verify both Type A and Type B devices shall be at least 0.005 mm for 5 mm and 10 mm
ball tests and at least 0.001 mm for 2.5 mm and 1 mm ball tests.
A1.3.3.1 For Type A devices, the error between the stage micrometer and the measuring device over each interval shall not exceed
the Type A minimum indicator resolution shown in Table 2 for the size of ball to be used.
A1.3.3.2 For Type B devices, it is not possible to determine a quantitative error value. Position the measuring device such that
the lines of the measuring device line-up with the lines of the stage micrometer as closely as possible. If any lines of the measuring
device do not, at least partially, overlap the corresponding lines of the stage micrometer, then the measuring device shall be
adjusted.
E10 − 23
A1.3.4 Verification of the Testing Cycle—The testing machine shall be verified to be capable of meeting the testing cycle tolerances
specified in 7.5. Direct verification of the testing cycle is to be verified by the testing machine manufacturer at the time of
manufacture, or when the testing machine is returned to the manufacturer for repair, or when a problem with the testing cycle is
suspected. Verification of the testing cycle is recommended but not required as part of the direct verification at other times.
A1.3.5 Direct Verification Failure—If any of the direct verifications fail the specified requirements, the testing machine shall not
be used until it is adjusted or repaired. If the test forces, indentation measuring system or testing cycle may have been affected by
an adjustment or repair, the affected components shall be verified again by a direct verification.
A1.4 Indirect Verification
A1.4.1 An indirect verification of the testing machine shall be performed in accordance with the schedule given in Table A1.1
Indirect verifications may be required more frequently than stated in Table A1.1 and should be based on the usage of the testing
machine.
A1.4.2 The testing machine shall be verified for each test force and for each ball diameter that will be used prior to the next
indirect verification. Hardness tests made using Brinell scales that have not been verified within the schedule given in Table A1.1
do not meet this standard.
A1.4.3 Standardized test blocks used for the indirect verification shall meet the requirements of Annex A4. Hardness
measurements shall be made only on the calibrated surface of the test block.
NOTE A1.3—It is recognized that appropriate standardized test blocks are not available for all geometric shapes, materials, or hardness ranges.
A1.4.4 As-found Condition—It is recommended that the as-found condition of the testing machine be assessed as part of an
indirect verification. This is important for documenting the historical performance of the machine. This procedure should be
conducted by the verification agency prior to any cleaning, maintenance, adjustments, or repairs.
A1.4.4.1 When the as-found condition of the testing machine is assessed, the assessment shall be made using the user’s indenter
ball that is normally used with the testing machine.
A1.4.4.2 One or more standardized test blocks in the range of normal testing should be tested for each Brinell scale that will
undergo indirect verification.
A1.4.4.3 On each standardized test block, make at least two Brinell hardness tests distributed uniformly over the test surface.
Determine the repeatability R and the error E (Eq 3 and Eq 5) in the performance of the testing machine for each standardized test
block that is measured.
A1.4.4.4 The repeatability R and the error E should be within the tolerances of Table A1.2. If the calculated values of the
repeatability R or the error E fall outside the specified tolerances, this is an indication that the hardness tests made since the last
indirect verification may be suspect.
E10 − 23
TABLE A1.2 Repeatability and Error of the Testing Machine
Maximum Permissible
Reference Block Maximum Permissible
Repeatability, R
Hardness Error, E
¯
HBW % of d % of H
(See Eq 3) (See Eq 5)
HBW # 125 3 3
125 < HBW # 225 2.5 3
HBW > 225 2 3
A1.4.5 Cleaning and Maintenance—Perform cleaning and routine maintenance of the testing machine (when required) in
accordance with the manufacturer’s specifications and instructions.
A1.4.6 Indirect Verification Procedure—The indirect verification procedure is designed to verify that for all of the Brinell hardness
scales to be used, each test force is being accurately applied, each indenter-ball size is correct, and the measuring device is
calibrated correctly for the range of indentation sizes that these scales produce. This is accomplished by making Brinell hardness
tests on test blocks that have been calibrated for appropriate Brinell hardness scales that employ each of the corresponding test
forces and indenter ball sizes.
A1.4.6
...