ASTM F879-15(2020)

Standard Specification for Stainless Steel Socket Button and Flat Countersunk Head Cap Screws

ABSTRACT
This specification covers the chemical and mechanical requirements for stainless steel metric hexagon socket button (SBHCS) and flat countersunk (SFHCS) head cap screws with nominal thread M 3 through M 20 intended for use in applications requiring general corrosion resistance. These steels are designated into three classes: Austenitic Class A 1-50 in an annealed condition, Austenitic Class A1-55 in a cold worked condition, and Austenitic Class A 1-70 in a cold worked condition. The austenitic stainless steel socket screw shall be designated F879M A1-50, F879M A1–55, or F 879M A1-70. Screws shall be formed by upsetting or extruding, or both. Also, these screws shall be roll threaded. Austenitic alloys ClassA 1-50 screws, following manufacture, shall be annealed by heating to a certain temperature to obtain maximum corrosion resistance and minimum permeability. The screws shall be held for a sufficient time at temperature, then cooled at a rate sufficient to prevent precipitation of the carbide and provide the properties specified. Different tests shall be conducted in order to determine the following mechanical properties of screws: tensile strength, minimum extension, yield strength, elongation, Vickers hardness, and Rockwell hardness.
SCOPE
1.1 This specification covers the chemical and mechanical requirements for stainless steel inch hexagon socket button (SBHCS) and flat countersunk (SFHCS) head cap screws with nominal thread 0.060 through 0.625 in. intended for use in applications requiring general corrosion resistance.  
1.2 Two groups of austenitic stainless steel alloys and three conditions are covered. See Table 1 and Table 2.    
1.3 Units—The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 The following precautionary caveat pertains only to the test method portion, Section 12, of this specification: 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.  
1.5 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: Historical
• Publication Date: 31-Mar-2020
• ICS: 21.060.10 - Bolts, screws, studs
• Technical Committee: F16 - Fasteners
• Drafting Committee: F16.04 - Nonferrous Fasteners

Standards Content (Sample)

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
Designation: F879 − 15 (Reapproved 2020)
Standard Specification for
Stainless Steel Socket Button and Flat Countersunk Head
1
Cap Screws
This standard is issued under the fixed designation F879; 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* A380/A380M Practice for Cleaning, Descaling, and Passi-
vation of Stainless Steel Parts, Equipment, and Systems
1.1 This specification covers the chemical and mechanical
A555/A555M Specification for General Requirements for
requirements for stainless steel inch hexagon socket button
Stainless Steel Wire and Wire Rods
(SBHCS) and flat countersunk (SFHCS) head cap screws with
A751 Test Methods, Practices, and Terminology for Chemi-
nominal thread 0.060 through 0.625 in. intended for use in
cal Analysis of Steel Products
applications requiring general corrosion resistance.
A967/A967M Specification for Chemical Passivation Treat-
1.2 Two groups of austenitic stainless steel alloys and three
ments for Stainless Steel Parts
conditions are covered. See Table 1 and Table 2.
D3951 Practice for Commercial Packaging
1.3 Units—The values stated in inch-pound units are to be E18 Test Methods for Rockwell Hardness of Metallic Ma-
terials
regarded as standard. No other units of measurement are
included in this standard. E92 Test Methods for Vickers Hardness and Knoop Hard-
ness of Metallic Materials
1.4 The following precautionary caveat pertains only to the
E384 Test Method for Microindentation Hardness of Mate-
test method portion, Section 12, of this specification: This
rials
standard does not purport to address all of the safety concerns,
F593 Specification for Stainless Steel Bolts, Hex Cap
if any, associated with its use. It is the responsibility of the user
Screws, and Studs
of this standard to establish appropriate safety, health, and
F606/F606M Test Methods for Determining the Mechanical
environmental practices and determine the applicability of
Properties of Externally and Internally Threaded
regulatory limitations prior to use.
Fasteners, Washers, Direct Tension Indicators, and Rivets
1.5 This international standard was developed in accor-
F788 Specification for Surface Discontinuities of Bolts,
dance with internationally recognized principles on standard-
Screws, and Studs, Inch and Metric Series
ization established in the Decision on Principles for the
F1470 Practice for Fastener Sampling for Specified Me-
Development of International Standards, Guides and Recom-
chanical Properties and Performance Inspection
mendations issued by the World Trade Organization Technical
2.2 ASME Standard:
Barriers to Trade (TBT) Committee.
3
B 18.3 Socket Cap, Shoulder and Set Screws (Inch Series)
4
2. Referenced Documents
2.3 JIS Standard:
2
JIS G 4309 Stainless Steel Wires
2.1 ASTM Standards:
A262 Practices for Detecting Susceptibility to Intergranular
3. Classification
Attack in Austenitic Stainless Steels
A342/A342M Test Methods for Permeability of Weakly
3.1 The designation of the alloy group and condition of this
Magnetic Materials
specification shall be consistent with the stainless steel desig-
nations in Specification F593.
1
This specification is under the jurisdiction of ASTM Committee F16 on
3.2 Screws shall be designated by group and condition (for
Fasteners and is the direct responsibility of Subcommittee F16.04 on Nonferrous
example, F879 Group 1 Condition AF).
Fasteners.
Current edition approved April 1, 2020. Published April 2020. Originally
approved in 1986. Last previous edition approved in 2015 as F879-15. DOI:
3
10.1520/F0879-15R20. Available from American Society of Mechanical Engineers (ASME), ASME
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM www.asme.org.
4
Standards volume information, refer to the standard’s Document Summary page on Available from Japanese Industrial Standards Committee (JIS) 1-3-1
the ASTM website. Kasumigaseki, Chiyoda-ku, Tokyo 100-8901, JAPAN. http://www.jisc.go.jp
*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
1

---------------------- Page: 1 ----------------------
F879 − 15 (2020)
TABLE 1 Mechanical Property Requirements
A B
Full Size Product Tests Machined Specimen Tests Core Hardness
Alloy
C
Alloy Group Tensile Tensile Yi
...

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: F879 − 15 F879 − 15 (Reapproved 2020)
Standard Specification for
Stainless Steel Socket Button and Flat Countersunk Head
1
Cap Screws
This standard is issued under the fixed designation F879; 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 specification covers the chemical and mechanical requirements for stainless steel inch hexagon socket button (SBHCS)
and flat countersunk (SFHCS) head cap screws with nominal thread 0.060 through 0.625 in. intended for use in applications
requiring general corrosion resistance.
1.2 Two groups of austenitic stainless steel alloys and three conditions are covered. See Table 1 and Table 2.
1.3 Units—The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included
in this standard.
1.4 The following precautionary caveat pertains only to the test method portion, Section 12, of this specification: 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 safety, health, and healthenvironmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 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
2.1 ASTM Standards:
A262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
A342/A342M Test Methods for Permeability of Weakly Magnetic Materials
A380/A380M Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems
A555/A555M Specification for General Requirements for Stainless Steel Wire and Wire Rods
A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
A967/A967M Specification for Chemical Passivation Treatments for Stainless Steel Parts
D3951 Practice for Commercial Packaging
E18 Test Methods for Rockwell Hardness of Metallic Materials
E92 Test Methods for Vickers Hardness and Knoop Hardness of Metallic Materials
E384 Test Method for Microindentation Hardness of Materials
F593 Specification for Stainless Steel Bolts, Hex Cap Screws, and Studs
F606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners,
Washers, Direct Tension Indicators, and Rivets
F788 Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series
F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
2.2 ASME Standard:
3
B 18.3 Socket Cap, Shoulder and Set Screws (Inch Series)
1
This specification is under the jurisdiction of ASTM Committee F16 on Fasteners and is the direct responsibility of Subcommittee F16.04 on Nonferrous Fasteners.
Current edition approved May 1, 2015April 1, 2020. Published July 2015April 2020. Originally approved in 1986. Last previous edition approved in 20122015 as
F879-12.-15. DOI: 10.1520/F0879-15.10.1520/F0879-15R20.
2
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.
3
Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org.
*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
1

---------------------- Page: 1 ----------------------
F879 − 15 (2020)
TABLE 1 Mechanical Property Requirements
A B
Full Size Product Tests Machined Specimen Tests Core Hardness
Alloy
C
Alloy Group
Tensile Extension Tensile Yield Elongation
Condition Vickers Rockwell
min
Strength ksi Strength ksi Strength ksi % min
All AF 85 max 0.6D 85 max 55 max 40 210 max 95 H
...