Standard Test Methods for Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials

SCOPE
1.1 These test methods cover the determination of the Rockwell hardness and the Rockwell superficial hardness of metallic materials, including test methods for the verification of machines for Rockwell hardness testing (Part B) and the calibration of standardized hardness test blocks (Part C).
1.2 Values stated in inch-pound units are to be regarded as the standard. SI units are provided for information only.
1.3 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 and health practices and determine the applicability of regulatory limitations prior to use. (See Note 6.)
Note 1—The National Institute of Standards and Technology (NIST) maintains the national Rockwell hardness standards for the United States. In June 1998, NIST released new Rockwell C scale (HRC) test blocks as Standard Reference Materials (SRMs). The blocks were calibrated using NIST's primary reference standardizing machine. The major benefit of the NIST standards is that their HRC levels are in line with the other industrialized countries around the world. The NIST HRC levels establish the hardness of materials slightly harder than the historical standards used in the United States for the past 75 years. The revision of E 18 requires that all performance verifications of Rockwell hardness indenters and hardness machines must be made using test blocks calibrated traceable to the Rockwell standards maintained by NIST. This can be accomplished through the use of commercial test blocks calibrated traceable to the NIST standards or by directly using the NIST SRMs. This requirement will apply only to the Rockwell scale(s) for which NIST supplies primary reference test blocks.
Note 2—In previous editions of this standard, ball indenters were required to be of hard steel. Beginning with this edition, tungsten-carbide balls are also allowed. This change is a first step in a planned future transition to eliminate steel balls and allow only the use of tungsten carbide balls. The elimination of steel ball indenters is scheduled to occur in about two years. The use of tungsten carbide balls will provide an improvement to the Rockwell hardness test because of the tendency of steel balls to flatten with use, which results in an erroneously elevated hardness value. In addition, NIST is planning to standardize the HRB scale using tungsten-carbide balls. As a result of this change, this edition also requires that when a ball indenter is used, the Rockwell hardness value must be reported with the scale designation followed by the letter "S" to indicate the use of a steel ball or the letter "W" to indicate the use of a tungsten carbide ball. The user is cautioned that Rockwell hardness tests comparing the use of steel and tungsten carbide balls have been shown to give different results. For example, depending on the material tested and its hardness level, Rockwell B scale tests using a tungsten carbide ball indenter have given results up to one Rockwell point lower than when a steel ball indenter is used.

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Historical
Publication Date
09-Jun-2003
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ASTM E18-03e1 - Standard Test Methods for Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
e1
Designation: E 18 – 03
Standard Test Methods for
Rockwell Hardness and Rockwell Superficial Hardness of
,
1 2
Metallic Materials
ThisstandardisissuedunderthefixeddesignationE18;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1
e NOTE—Table 15 was editorially revised in June 2004.
in about two years. The use of tungsten carbide balls will provide an
1. Scope*
improvement to the Rockwell hardness test because of the tendency of
1.1 These test methods cover the determination of the
steel balls to flatten with use, which results in an erroneously elevated
Rockwell hardness and the Rockwell superficial hardness of
hardness value. In addition, NIST is planning to standardize the HRB
metallic materials, including test methods for the verification
scale using tungsten-carbide balls.As a result of this change, this edition
of machines for Rockwell hardness testing (Part B) and the also requires that when a ball indenter is used, the Rockwell hardness
value must be reported with the scale designation followed by the letter
calibration of standardized hardness test blocks (Part C).
“S” to indicate the use of a steel ball or the letter “W” to indicate the use
1.2 Values stated in inch-pound units are to be regarded as
of a tungsten carbide ball. The user is cautioned that Rockwell hardness
the standard. SI units are provided for information only.
tests comparing the use of steel and tungsten carbide balls have been
1.3 This standard does not purport to address all of the
shown to give different results. For example, depending on the material
safety concerns, if any, associated with its use. It is the
tested and its hardness level, Rockwell B scale tests using a tungsten
responsibility of the user of this standard to establish appro-
carbide ball indenter have given results up to one Rockwell point lower
than when a steel ball indenter is used.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. (See Note 6.)
2. Referenced Documents
NOTE 1—The National Institute of Standards and Technology (NIST)
2.1 ASTM Standards:
maintains the national Rockwell hardness standards for the United States.
A370 TestMethodsandDefinitionsforMechanicalTesting
In June 1998, NIST released new Rockwell C scale (HRC) test blocks as
3
of Steel Products
Standard Reference Materials (SRMs). The blocks were calibrated using
B19 Specification for Cartridge Brass Sheet, Strip, Plate,
NIST’sprimaryreferencestandardizingmachine.Themajorbenefitofthe
4
NIST standards is that their HRC levels are in line with the other
Bar, and Disks (Blanks)
industrializedcountriesaroundtheworld.TheNISTHRClevelsestablish
B36/B36 M Specification for Brass Plate, Sheet, Strip, and
the hardnessofmaterialsslightlyharderthanthehistoricalstandardsused 4
Rolled Bar
in the United States for the past 75 years. The revision of E 18 requires
B96 Specification for Copper-Silicon Alloy Plate, Sheet,
that all performance verifications of Rockwell hardness indenters and
Strip, and Rolled Bar for General Purposes and Pressure
hardness machines must be made using test blocks calibrated traceable to
4
Vessels
the Rockwell standards maintained by NIST. This can be accomplished
throughtheuseofcommercialtestblockscalibratedtraceabletotheNIST B97 Specification for Copper-Silicon Alloy Plate, Sheet,
5
standards or by directly using the NIST SRMs. This requirement will
Strip, and Rolled Bar for General Purposes
apply only to the Rockwell scale(s) for which NIST supplies primary
B103/B103 M Specification for Phosphor Bronze Plate,
reference test blocks 4
Sheet, Strip, and Rolled Bar
NOTE 2—In previous editions of this standard, ball indenters were
B121/B121 M Specification for Leaded Brass Plate,
required to be of hard steel. Beginning with this edition, tungsten-carbide
4
Sheet, Strip, and Rolled Bar
balls are also allowed. This change is a first step in a planned future
B122/B122 MSpecificationforCopper-Nickel-TinAlloy,
transition to eliminate steel balls and allow only the use of tungsten
carbide balls.The elimination of steel ball indenters is scheduled to occur
Copper-Nickel-Zinc Alloy (Nickel Silver), and Copper-
4
Nickel Alloy Plate, Sheet, Strip, and Rolled Bar
B130 SpecificationforCommercialBronzeStripforBullet
1
4
These test methods are under the jurisdiction of ASTM Committee E28 on
Jackets
Mechanical Testing and are the direct responsibility of Subcommittee E28.06 on 4
B134 Specification for Brass Wire
Indentation Hardness Testing.
Current edition approve
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