ASTM A320/A320M-15
(Specification)Standard Specification for Alloy-Steel and Stainless Steel Bolting for Low-Temperature Service
Standard Specification for Alloy-Steel and Stainless Steel Bolting for Low-Temperature Service
ABSTRACT
This specification covers alloy steel bolting materials for pressure vessels, valves, flanges, and fittings for low-temperature service. Each alloy shall conform to the prescribed chemical composition requirements. The material, as represented by the tension specimens, shall conform to the requirements as to tensile properties such as tensile strength, yield strength, elongation, and hardness. The material shall meet the prescribed impact energy absorption requirements and the recommended test temperature. Mechanical tests shall be conducted on the material, namely: impact testing, tension testing, and hardness testing.
SCOPE
1.1 This specification2 covers alloy steel bolting for pressure vessels, valves, flanges, and fittings for low-temperature service. See Specification A962/A962M for the definition of bolting. The bars shall be hot-wrought and may be further processed by centerless grinding or by cold drawing. Austenitic stainless steel may be solution annealed or annealed and strain-hardened. When strain hardened austenitic stainless steel is ordered, the purchaser should take special care to ensure that Appendix X1 is thoroughly understood.
1.2 Several grades are covered, including both ferritic and austenitic steels designated L7, B8, etc. Selection will depend on design, service conditions, mechanical properties, and low-temperature characteristics. The mechanical requirements of Table 1 indicate the diameters for which the minimum mechanical properties apply to the various grades and classes, and Table 2 stipulates the requirements for Charpy impact energy absorption. The manufacturer should determine that the material can conform to these requirements before parts are manufactured. For example, when Grade L43 is specified to meet the Table 2 impact energy values at −150 °F [−101 °C], additional restrictions (such as procuring a steel with lower P and S contents than might normally be supplied) in the chemical composition for AISI 4340 are likely to be required.
Note 1: The committee formulating this specification has included several grades of material that have been rather extensively used for the present purpose. Other compositions will be considered for inclusion by the committee from time to time as the need becomes apparent. Users should note that hardenability of some of the grades mentioned may restrict the maximum size at which the required mechanical properties are obtainable. (A) These upper diameter limits were established on the basis that these were the largest sizes commonly available that consistently met specification property limits. They are not intended as absolute limits beyond which bolting materials could no longer be certified to the specification.(B) To meet the tensile requirements, the Brinell hardness shall not be less than 200 HBW or 93 HRB.(C) Class 1 products are made from solution-treated material. Class 1A products are solution treated in the finished condition for corrosion resistance; heat treatment is critical for enhancing this physical property and meeting the mechanical property requirements. Class 2 products are made from solution-treated material that has been strain hardened. Austenitic steels in the strain-hardened condition may not show uniform properties throughout the cross section, particularly in sizes over 3/4 in. [20 mm] in diameter.(D) For sizes 3/4 in. [20 mm] in diameter and smaller, a maximum hardness of 241 HBW (100 HRB) is permitted. (A) See 6.2.1.1 for permitted exemptions.
1.3 The following referenced general requirements are indispensable for application of this specification: Specification A962/A962M.
1.4 Nuts for use with bolting are covered in Section 10 and the nut material shall be impact tested.
1.5 Supplementary Requirements are provided for use at the option of the purchaser. The supplementary requirements shall apply only when specified in the purchase order or contract.
1.6 This specification is expressed ...
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Designation: A320/A320M −15
StandardSpecification for
Alloy-Steel and Stainless Steel Bolting for Low-Temperature
1
Service
This standard is issued under the fixed designationA320/A320M; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 1.3 The following referenced general requirements are in-
dispensable for application of this specification: Specification
2
1.1 This specification covers alloy steel bolting for pres-
A962/A962M.
sure vessels, valves, flanges, and fittings for low-temperature
1.4 Nuts for use with bolting are covered in Section 10 and
service. See Specification A962/A962M for the definition of
the nut material shall be impact tested.
bolting. The bars shall be hot-wrought and may be further
processedbycenterlessgrindingorbycolddrawing.Austenitic
1.5 SupplementaryRequirementsareprovidedforuseatthe
stainless steel may be solution annealed or annealed and
option of the purchaser. The supplementary requirements shall
strain-hardened.Whenstrainhardenedausteniticstainlesssteel apply only when specified in the purchase order or contract.
isordered,thepurchasershouldtakespecialcaretoensurethat
1.6 This specification is expressed in both inch-pound units
Appendix X1 is thoroughly understood.
and SI units; however, unless the purchase order or contract
specifies the applicable M specification designation (SI) units,
1.2 Several grades are covered, including both ferritic and
the inch-pound units shall apply.
austenitic steels designated L7, B8, etc. Selection will depend
on design, service conditions, mechanical properties, and
1.7 The values stated in either SI units or inch-pound units
low-temperature characteristics. The mechanical requirements
are to be regarded separately as standard. The values stated in
of Table 1 indicate the diameters for which the minimum
each system may not be exact equivalents; therefore, each
mechanical properties apply to the various grades and classes,
system shall be used independently of the other. Combining
and Table 2 stipulates the requirements for Charpy impact
values from the two systems may result in non-conformance
energyabsorption.Themanufacturershoulddeterminethatthe
with the standard.
material can conform to these requirements before parts are
2. Referenced Documents
manufactured. For example, when Grade L43 is specified to
3
meet the Table 2 impact energy values at −150 °F [−101 °C],
2.1 ASTM Standards:
additional restrictions (such as procuring a steel with lower P
A194/A194MSpecificationforCarbonandAlloySteelNuts
and S contents than might normally be supplied) in the
for Bolts for High Pressure or High Temperature Service,
chemical composition forAISI 4340 are likely to be required.
or Both
A370Test Methods and Definitions for Mechanical Testing
NOTE 1—The committee formulating this specification has included
of Steel Products
several grades of material that have been rather extensively used for the
A962/A962MSpecification for Common Requirements for
present purpose. Other compositions will be considered for inclusion by
the committee from time to time as the need becomes apparent. Users
Bolting Intended for Use atAny Temperature from Cryo-
should note that hardenability of some of the grades mentioned may
genic to the Creep Range
restrictthemaximumsizeatwhichtherequiredmechanicalpropertiesare
E566PracticeforElectromagnetic(EddyCurrent)Sortingof
obtainable.
Ferrous Metals
F436Specification for Hardened Steel Washers
F606Test Methods for Determining the Mechanical Proper-
1
This specification is under the jurisdiction ofASTM Committee A01 on Steel,
ties of Externally and Internally Threaded Fasteners,
Stainless Steel and Related Alloysand is the direct responsibility of Subcommittee
Washers, and Rivets (Metric) F0606_F0606M
A01.22onSteelForgingsandWroughtFittingsforPipingApplicationsandBolting
Materials for Piping and Special Purpose Applications.
Current edition approved May 1, 2015. Published May 2015. Originally
3
approved in 1948. Last previous edition approved in 2014 as A320/A320M–14. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/A0320_A0320M-15. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
2
For ASME Boiler and Pressure Vessel Code applications, see related Specifi- Standards volume information, refer to the standard’s Document Summary page on
cation SA-320 in Section II of that Code. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 1
...
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: A320/A320M − 14 A320/A320M − 15
Standard Specification for
Alloy-Steel and Stainless Steel Bolting for Low-Temperature
1
Service
This standard is issued under the fixed designation A320/A320M; 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*
2
1.1 This specification covers alloy steel bolting for pressure vessels, valves, flanges, and fittings for low-temperature service.
See Specification A962/A962M for the definition of bolting. The bars shall be hot-wrought and may be further processed by
centerless grinding or by cold drawing. Austenitic stainless steel may be solution annealed or annealed and strain-hardened. When
strain hardened austenitic stainless steel is ordered, the purchaser should take special care to ensure that Appendix X1 is thoroughly
understood.
1.2 Several grades are covered, including both ferritic and austenitic steels designated L7, B8, etc. Selection will depend on
design, service conditions, mechanical properties, and low-temperature characteristics. The mechanical requirements of Table 1
indicate the diameters for which the minimum mechanical properties apply to the various grades and classes, and Table 2 stipulates
the requirements for Charpy impact energy absorption. The manufacturer should determine that the material can conform to these
requirements before parts are manufactured. For example, when Grade L43 is specified to meet the Table 2 impact energy values
at −150 °F [−101 °C], additional restrictions (such as procuring a steel with lower P and S contents than might normally be
supplied) in the chemical composition for AISI 4340 are likely to be required.
NOTE 1—The committee formulating this specification has included several grades of material that have been rather extensively used for the present
purpose. Other compositions will be considered for inclusion by the committee from time to time as the need becomes apparent. Users should note that
hardenability of some of the grades mentioned may restrict the maximum size at which the required mechanical properties are obtainable.
1.3 The following referenced general requirements are indispensable for application of this specification: Specification
A962/A962M.
1.4 Nuts for use with bolting are covered in Section 10 and the nut material shall be impact tested.
1.5 Supplementary Requirements are provided for use at the option of the purchaser. The supplementary requirements shall
apply only when specified in the purchase order or contract.
1.6 This specification is expressed in both inch-pound units and SI units; however, unless the purchase order or contract
specifies the applicable M specification designation (SI) units, the inch-pound units shall apply.
1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
2. Referenced Documents
3
2.1 ASTM Standards:
A194/A194M Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service, or Both
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A962/A962M Specification for Common Requirements for Bolting Intended for Use at Any Temperature from Cryogenic to the
Creep Range
1
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloysand is the direct responsibility of Subcommittee A01.22
on Steel Forgings and Wrought Fittings for Piping Applications and Bolting Materials for Piping and Special Purpose Applications.
Current edition approved May 1, 2014May 1, 2015. Published May 2014May 2015. Originally approved in 1948. Last previous edition approved in 20112014 as
A320/A320M–11a.–14. DOI: 10.1520/A0320_A0320M-14.10.1520/A0320_A0320M-15.
2
For ASME Boiler and Pressure Vessel Code applications, see related Specification SA-320 in Section II of that Code.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the st
...
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