ASTM A838-18

Standard Specification for Free-Machining Ferritic Stainless Soft Magnetic Alloy Bar for Relay Applications

ABSTRACT
This specification covers nominally 17.5% Cr free-machining ferritic stainless soft magnetic alloy produced or supplied expressly in cold-finished bar form for use in magnetic cores and other parts requiring a corrosion-resistant, high permeability, low-coercivity steel. This specification does not cover either cast parts or parts produced by powder metallurgy techniques. Two specific alloy types are covered distinguished by different silicon levels. Required measurements include chemical analysis and dc magnetic property measurement. The magnetic properties depend both on the grade and the dimensions. Apart from the requirements, the specification contains useful appendices discussing the magnetic testing of these alloys and typical magnetic and physical properties.
SCOPE
1.1 This specification covers free-machining ferritic stainless soft magnetic alloy produced or supplied expressly in cold-finished bar form for use in magnetic cores and other parts requiring a high permeability, low-coercivity stainless steel.  
1.1.1 This specification does not cover either cast parts or parts produced by powder metallurgy techniques.  
1.2 Two specific alloy types are covered. The primary constituents are shown in Table 1. These types have corrosion resistance similar to AISI Type 430F and Type 430F, Specification A582/A582M.  
1.3 This specification covers only these alloy types supplied in cold-finished bars in cross-sectional shapes such as rounds, squares, hexagons, and octagons with diameters (diagonals) greater than or equal to 6.35 mm (0.250 in.) and less than or equal to 41.5 mm (1.63 in.).2  
1.4 Certain cold-finished round bar products are capable of being supplied mill annealed to required magnetic properties such as low coercivity. The size range that can be mill annealed is from 6.35 to 41.5 mm (0.250 to 1.63 in.). Other products of these alloys cannot be mill annealed to produce equivalently low coercivity; hence, the final machined parts should be heat treated as recommended by the producer.  
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to customary (cgs-emu and inch-pound) units which are provided for information only and are not considered standard.  
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-Sep-2018
• ICS: 77.140.40 - Steels with special magnetic properties
• Technical Committee: A06 - Magnetic Properties
• Drafting Committee: A06.02 - Material Specifications

Relations

• Refers: ASTM A340-23a - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 01-Dec-2023
• Refers: ASTM A340-19b - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 15-Oct-2019
• Refers: ASTM A340-19a - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 15-Jun-2019
• Refers: ASTM A340-19 - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 15-Feb-2019
• Refers: ASTM A340-18 - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 01-Jun-2018
• Refers: ASTM A340-17a - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 15-Oct-2017
• Refers: ASTM A340-17 - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 01-Jul-2017
• Refers: ASTM A340-16e1 - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 01-May-2016
• Refers: ASTM A340-16 - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 01-May-2016
• Refers: ASTM A340-15 - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 01-Oct-2015
• Refers: ASTM A340-14 - Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• Effective Date: 01-Oct-2014
• Refers: ASTM A34/A34M-06(2012) - Standard Practice for Sampling and Procurement Testing of Magnetic Materials
• Effective Date: 01-Nov-2012
• Refers: ASTM A582/A582M-12 - Standard Specification for Free-Machining Stainless Steel Bars
• Effective Date: 01-Mar-2012
• Refers: ASTM A582/A582M-12e1 - Standard Specification for Free-Machining Stainless Steel Bars
• Effective Date: 01-Mar-2012
• Refers: ASTM A341/A341M-00(2011) - Standard Test Method for Direct Current Magnetic Properties of Materials Using D-C Permeameters and the Ballistic Test Methods
• Effective Date: 01-Oct-2011

Overview

ASTM A838-18 is the standard specification developed by ASTM International for free-machining ferritic stainless soft magnetic alloy bar used primarily in relay and magnetic core applications. This standard defines the requirements for cold-finished bar forms of nominally 17.5% chromium grade, explicitly designed for use where both corrosion resistance and soft magnetic properties, such as high permeability and low coercivity, are critical. It distinguishes between two alloy types with different silicon levels and covers relevant measurement and testing details to ensure product consistency and performance.

This standard does not address cast parts or parts produced by powder metallurgy, focusing solely on cold-finished bars in specified cross-sectional shapes and diameters.

Key Topics

• Scope of Coverage

  • Applies to cold-finished bar forms only, not cast or powder-metallurgy products
  • Two alloy types with specific chemical compositions, primarily varying by silicon content
  • Size range covers diameters (or diagonals) from 6.35 mm (0.250 in.) to 41.5 mm (1.63 in.)

• Alloy Types and Grades

  • Alloy Type 1 and Alloy Type 2 differ in silicon content
  • Multiple grades distinguished by condition (mill annealed, cold drawn) and associated magnetic properties

• Magnetic and Mechanical Property Requirements

  • Tests for coercive field strength (coercivity) and permeability
  • Measurement techniques include ring, permeameter, or coercimeter tests following referenced ASTM and IEC standards
  • Minimum requirements for mechanical strength and hardness, although typical property ranges are provided for reference

• Ordering and Identification

  • Clear instructions for purchase orders, requiring reference to this specification, alloy type and grade, dimensions, quantity, and any special requirements

• Packaging and Certification

  • Packaging and marking agreements between supplier and user to ensure traceability
  • Certification of compliance and test results as per user needs

Applications

• Magnetic Cores and Relays

  • Ideal for parts in electromechanical relays and contactors needing soft magnetic characteristics for efficient electromagnetic performance

• Corrosion-Resistant Magnetic Components

  • Suitable for environments where both magnetic performance and resistance to atmospheric and chemical corrosion are required

• Electrical and Electronic Equipment

  • Used in various switchgear, solenoid cores, control system components, and other equipment demanding precisely controlled magnetic properties

• Precision Machined Parts

  • Free-machining characteristics enable efficient fabrication of intricate and tightly-toleranced components including bars in round, square, hexagonal, or octagonal forms

Related Standards

• ASTM A34/A34M – Practice for Sampling and Procurement Testing of Magnetic Materials
• ASTM A340 – Terminology of Symbols and Definitions Relating to Magnetic Testing
• ASTM A341/A341M – Test Method for Direct Current Magnetic Properties of Soft Magnetic Materials Using D-C Permeameters and Ballistic Test Methods
• ASTM A582/A582M – Specification for Free-Machining Stainless Steel Bars
• ASTM A596/A596M – Test Method for Direct-Current Magnetic Properties Using the Ballistic Method and Ring Specimens
• ASTM A773/A773M – Test Method for Magnetic Properties of Low Coercivity Magnetic Materials Using Hysteresigraphs
• ASTM E1019 – Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen
• IEC 60404-7 – Methods of Measurement of the Coercivity of Magnetic Materials in an Open Magnetic Circuit

Practical Value

Conformance to ASTM A838-18 ensures reliable supply of stainless steel bar with predictable, well-documented soft magnetic and free-machining properties. This specification is vital for industries that manufacture magnetic relay components, electromagnetic devices, and corrosion-resistant precision parts. Adoption of this standard reduces risk in quality control, material sourcing, and downstream performance, offering internationally recognized guidelines for both buyers and producers.

Keywords: ASTM A838-18, free-machining ferritic stainless, soft magnetic alloy, relay applications, high permeability, low coercivity, magnetic cores, corrosion-resistant steel, cold-finished bar, magnetic testing.

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:A838 −18
Standard Specification for
Free-Machining Ferritic Stainless Soft Magnetic Alloy Bar
for Relay Applications
This standard is issued under the fixed designation A838; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 This specification covers free-machining ferritic stain-
1.7 This international standard was developed in accor-
less soft magnetic alloy produced or supplied expressly in
dance with internationally recognized principles on standard-
cold-finishedbarformforuseinmagneticcoresandotherparts
ization established in the Decision on Principles for the
requiring a high permeability, low-coercivity stainless steel.
Development of International Standards, Guides and Recom-
1.1.1 This specification does not cover either cast parts or
mendations issued by the World Trade Organization Technical
parts produced by powder metallurgy techniques.
Barriers to Trade (TBT) Committee.
1.2 Two specific alloy types are covered. The primary
constituents are shown in Table 1. These types have corrosion
2. Referenced Documents
resistance similar to AISI Type 430F and Type 430F, Specifi-
cation A582/A582M.
2.1 ASTM Standards:
A34/A34MPractice for Sampling and Procurement Testing
1.3 Thisspecificationcoversonlythesealloytypessupplied
of Magnetic Materials
in cold-finished bars in cross-sectional shapes such as rounds,
A340Terminology of Symbols and Definitions Relating to
squares, hexagons, and octagons with diameters (diagonals)
Magnetic Testing
greater than or equal to 6.35 mm (0.250 in.) and less than or
A341/A341MTest Method for Direct Current Magnetic
equal to 41.5 mm (1.63 in.).
Properties of Soft Magnetic Materials Using D-C Per-
1.4 Certain cold-finished round bar products are capable of
meametersandthePointbyPoint(Ballistic)TestMethods
being supplied mill annealed to required magnetic properties
A582/A582MSpecification for Free-Machining Stainless
suchaslowcoercivity.Thesizerangethatcanbemillannealed
Steel Bars
is from 6.35 to 41.5 mm (0.250 to 1.63 in.). Other products of
A596/A596MTest Method for Direct-Current Magnetic
these alloys cannot be mill annealed to produce equivalently
Properties of Materials Using the Ballistic Method and
low coercivity; hence, the final machined parts should be heat
Ring Specimens
treated as recommended by the producer.
A773/A773MTest Method for Direct Current Magnetic
1.5 The values stated in SI units are to be regarded as
Properties of Low Coercivity Magnetic Materials Using
standard. The values given in parentheses are mathematical
Hysteresigraphs
conversions to customary (cgs-emu and inch-pound) units
E1019Test Methods for Determination of Carbon, Sulfur,
whichareprovidedforinformationonlyandarenotconsidered
Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt
standard.
Alloys by Various Combustion and Inert Gas Fusion
Techniques
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
2.2 Other Standard:
responsibility of the user of this standard to establish appro-
IEC Publication 60404-7Methods of Measurement of the
Coercivity of Magnetic Materials in an Open Magnetic
Circuit
This specification is under the jurisdiction of ASTM Committee A06 on
Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on
Material Specifications.
Current edition approved Oct. 1, 2018. Published October 2018. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 1985. Last previous edition approved in 2013 as A838–02 (2013). contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
DOI: 10.1520/A0838-18. Standards volume information, refer to the standard’s Document Summary page on
Other product forms can be supplied to the chemistries listed in this specifi- the ASTM website.
cation; however, all other requirements shall be subject to negotiation between the Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
producer and the user. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A838−18
TABLE 1 Alloy Types TABLE 3 Grades for Alloy Type 2
Nominal Composition, Weight Percent Grade As-Supplied Condition
Alloy Type
Carbon Chromium Silicon Sulfur Iron 1 mill annealed
1 0.05 17.5 0.50 0.30 balance 2 unannealed, cold drawn
2 0.05 17.5 1.25 0.30 balance
7. Form and Condition
3. Terminology
7.1 Cold Finished Bars—Cold drawn; cold drawn and
centerless ground; cold drawn and precision ground; mill
3.1 The terms and symbols used in this specification are
annealed and centerless ground; mill annealed and precision
defined in Terminology A340.
ground.
4. Classification
8. Magnetic Property Requirements
4.1 Two specific alloy types are covered:
8.1 General—Material supplied under terms of this specifi-
4.2 Grades,Alloy Type 1—The standard grades of this alloy
cation shall be tested using either ring, permeameter, or
type are distinguished by the as-supplied condition, coercive
coercimeter test methods. Only the coercive field strength
field strength, and nominal mechanical hardness and are listed
(H )issubjecttospecification.Sincecoercimeterssaturatethe
cB
in Table 2.
test specimen before measurement of the coercive field
4.3 Grades,Alloy Type 2—The standard grades of this alloy strength, two different sets of coercive field strength
type are distinguished by the as-supplied condition, coercive requirements,oneforringandpermeametertestingandonefor
field strength, and nominal mechanical hardness and are listed coercimetertesting,aregiven.Unlessspecifiedinthepurchase
in Table 3. order, coercimeter testing shall be the standard test method.
8.2 TestSpecimen—Testspecimensizeandshapeshallbein
5. Ordering Information
accordance with the requirements listed in Practice A34/
A34M. If tests on heat-treated specimens are requested, all
5.1 Purchase orders for material under this specification
shall include the following information to adequately describe machiningoperationsshallbeperformedbeforeheattreatment.
The cross-sectional area of all specimen types shall be deter-
the desired product:
5.1.1 Reference to this specification and year of issue/ mined by measurement with a micrometer or calipers.
revision.
8.3 Magnetic Test Specimen Heat Treatment—When speci-
5.1.2 Alloy type and grade (Section 4),
fied on the purchase order, the annealed magnetic properties
5.1.3 Form and condition,
(also referred to as the magnetic capability) rather than the
5.1.4 Dimensions and tolerances (Section 9),
as-supplied magnetic properties shall be determined. The heat
5.1.5 Quantity (weight or number of pieces),
treatmenttobeusedtoassessthemagneticcapabilityshouldbe
5.1.6 Magneticpropertyrequirementsifotherthanshownin
specified by the user. If not, the following heat treatment
this specification.
procedure (full anneal) shall be used.
5.1.7 Certification of analysis or magnetic quality
8.3.1 Atmosphere—High vacuum or very dry hydrogen
evaluation, or both, if needed,
(dew point less than −60°C).
5.1.8 Marking and packaging, and
8.3.2 Soak Temperature (Alloy Type 1)—815 6 25°C.
5.1.9 Exceptions to the specification or special require-
8.3.3 Soak Temperature (Alloy Type 2)—850 6 2
...

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: A838 − 02 (Reapproved 2013) A838 − 18
Standard Specification for
Free-Machining Ferritic Stainless Soft Magnetic Alloy Bar
for Relay Applications
This standard is issued under the fixed designation A838; 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.
1. Scope
1.1 This specification covers free-machining ferritic stainless soft magnetic alloy produced or supplied expressly in
cold-finished bar form for use in magnetic cores and other parts requiring a high permeability, low-coercivity stainless steel.
1.1.1 This specification does not cover either cast parts or parts produced by powder metallurgy techniques.
1.2 Two specific alloy types are covered. The primary constituents are shown in Table 1. These types have corrosion resistance
similar to AISI Type 430F and Type 430F, Specification A582/A582M.
1.3 This specification covers only these alloy types supplied in cold-finished bars in cross-sectional shapes such as rounds,
squares, hexagons, and octagons with diameters (diagonals) greater than or equal to 0.250 in. (6.35 mm)6.35 mm (0.250 in.) and
less than or equal to 1.625 in. (41.28 mm).41.5 mm (1.63 in.).
1.4 Certain cold-finished round bar products are capable of being supplied mill annealed to required magnetic properties such
as low coercivity. The size range that can be mill annealed is from 0.250 to 1.625 in. (6.35 to 41.28 mm).6.35 to 41.5 mm (0.250
to 1.63 in.). Other products of these alloys cannot be mill annealed to produce equivalently low coercivity; hence, the final
machined parts should be heat treated as recommended by the producer.
1.5 The values stated in customary (cgs-emu and inch-pound) SI units are to be regarded as standard. The values given in
parentheses are mathematical conversions to SI customary (cgs-emu and inch-pound) units which are provided for information
only and are not considered standard.
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.
2. Referenced Documents
2.1 ASTM Standards:
A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials
A340 Terminology of Symbols and Definitions Relating to Magnetic Testing
A341/A341M Test Method for Direct Current Magnetic Properties of Soft Magnetic Materials Using D-C Permeameters and the
Point by Point (Ballistic) Test Methods
A582/A582M Specification for Free-Machining Stainless Steel Bars
A596/A596M Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens
A773/A773M Test Method for Direct Current Magnetic Properties of Low Coercivity Magnetic Materials Using Hysteresig-
raphs
This specification is under the jurisdiction of ASTM Committee A06 on Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on Material
Specifications.
Current edition approved May 1, 2013Oct. 1, 2018. Published July 2013October 2018. Originally approved in 1985. Last previous edition approved in 20072013 as
A838 – 02 (2007).(2013). DOI: 10.1520/A0838-02R13.10.1520/A0838-18.
Other product forms can be supplied to the chemistries listed in this specification; however, all other requirements shall be subject to negotiation between the producer
and the user.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A838 − 18
TABLE 1 Alloy Types
Nominal Composition, Weight Percent
Alloy Type
Carbon Chromium Silicon Sulfur Iron
1 0.05 17.5 0.50 0.30 balance
2 0.05 17.5 1.25 0.30 balance
E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by
Various Combustion and Inert Gas Fusion Techniques
2.2 Other Standard:
IEC Publication 60404-7 Methods of Measurement of the Coercivity of Magnetic Materials in an Open Magnetic Circuit
3. Terminology
3.1 The terms and symbols used in this specification are defined in Terminology A340.
4. Classification
4.1 Two specific alloy types are covered:
4.2 Grades, Alloy Type 1—The standard grades of this alloy type are distinguished by the as-supplied condition, coercivity,
coercive field strength, and nominal mechanical hardness and are listed in Table 2.
4.3 Grades, Alloy Type 2—The standard grades of this alloy type are distinguished by the as-supplied condition, coercivity,
coercive field strength, and nominal mechanical hardness and are listed in Table 3.
5. Ordering Information
5.1 Purchase orders for material under this specification shall include the following information to adequately describe the
desired product:
5.1.1 Reference to this specification and year of issue/revision.
5.1.2 Alloy type and grade (Section 4),
5.1.3 Form and condition,
5.1.4 Dimensions and tolerances (Section 9),
5.1.5 Quantity (weight or number of pieces),
5.1.6 Magnetic property requirements if other than shown in this specification.
5.1.7 Certification of analysis or magnetic quality evaluation, or both, if needed,
5.1.8 Marking and packaging, and
5.1.9 Exceptions to the specification or special requirements.
6. Chemical Composition
6.1 The material shall conform to the requirements prescribed in Table 4.
6.2 Determination of metallic constituents shall be by a method acceptable to both the producer and the user. Analysis of carbon,
nitrogen, sulfur, and oxygen shall be done in accordance with Test Methods E1019.
7. Form and Condition
7.1 Cold Finished Bars—Cold drawn; cold drawn and centerless ground; cold drawn and precision ground; mill annealed and
centerless ground; mill annealed and precision ground.
TABLE 2 Grades for Alloy Type 1
Grade As-Supplied Condition
1 mill annealed
2 mill annealed
3 unannealed, cold drawn
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
A838 − 18
TABLE 3 Grades for Alloy Type 2
Grade As-Supplied Condition
1 mill annealed
2 unannealed, cold drawn
8. Magnetic Property Requirements
8.1 General—Material supplied under terms of this specification shall be tested using either ring, permeameter, or coercimeter
test methods. Only the coercive field strength (H ) is subject to specification. Since coercimeters saturate the test specimen before
ccB
measurement of the coercive field strength, two different sets of coercive field strength requirements, one for ring and permeameter
testing and one for coercimeter testing, are given. Unless specified in the purchase order, coercimeter testing shall be the standard
test method.
8.2 Test Specimen—Test specimen size and shape shall be in accordance with the requirements listed in Practice A34/A34M.
If tests on heat-treated specimens are requested, all machining operations shall be performed before heat treatment. The
cross-sectional area of all specimen types shall be determined by measurement with a micrometer or calipers.
8.3 Magnetic Test Specimen Heat Treatment—When specified on the purchase order, the annealed magnetic properties (also
referred to as the magnetic capability) rather than the as-supplied magnetic properties shall be determined. The heat treatment to
be used to assess the magnetic capability should be specified by the user. If not, the following heat treatment procedure (full anneal)
shall be used.
8.3.1 Atmosphere—High vacuum or very dry hydrogen (dew point less than −60°C).
8.3.2 Soak Temperature (Alloy Type 1)—815 6 25°C.
8.3.3 Soak Temperature (Alloy Type 2)—850 6 25°C.
8.3.4 Soak Time—2-h minimum.
8.3.5 Cooling—Furnace cool (50 to 100°C/h) to 400°C then cool to room temperature at any convenient rate.
8.4 dc Ring and Permeameter Testing:
8.4.1 Either ring or permeameter test methods may be used. For ring testing, a link-type specimen with its long edge parallel
to the bar axis is preferred. Testing of ring or link specimens shall be in accordance with Test Methods A596/A596M or
A773/A773M. Testing of bar specimens on a permeameter shall be in accordance with either
...