ASTM F879-02a(2008)

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 hexagon socket button and flat countersunk head cap screws intended for use in applications requiring general corrosion resistance. The following three conditions are covered: austenitic alloy group 1 AF in an annealed condition, austenitic alloy group 1 CW in a cold-worked condition, and austenitic alloy group 1 CW1 in a cold worked condition. Screws shall be formed by upsetting or extruding, or both and shall be roll threaded and annealed to obtain maximum corrosion resistance and minimum permeability. The chemical composition, which shall be determined by chemical analysis, shall conform to the requirements for carbon, manganese, phosphorus, sulfur, silicon, chromium, nickel, copper, and molybdenum. The screws shall be subjected to tension tests and shall conform to the breaking strength, tensile strength, extension, yield strength, elongation, and Vickers and Rockwell hardness requirements. Corrosion test shall also be conducted to determine the susceptibility of the specimens to intergranular corrosion.
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 The following three conditions are covered:  
1.2.1 Austenitic alloy group 1 AF in an annealed condition at 85 ksi maximum,
1.2.2 Austenitic alloy group 1 CW in a cold-worked condition at 80 ksi minimum, and
1.2.3 Austenitic alloy group 1 condition CW1 in a cold worked condition at 102 ksi minimum.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Apr-2008
• ICS: 21.060.10 - Bolts, screws, studs
• Technical Committee: F16 - Fasteners
• Drafting Committee: F16.04 - Nonferrous Fasteners

Relations

• Replaces: ASTM F879-02a - Standard Specification for Stainless Steel Socket Button and Flat Countersunk Head Cap Screws
• Effective Date: 01-May-2008
• Replaced By: ASTM F879-10 - Standard Specification for Stainless Steel Socket Button and Flat Countersunk Head Cap Screws
• Effective Date: 01-May-2010
• Referred By: ASTM C1921/C1921M-22 - Standard Test Method for Comparative Impact Testing of Gypsum Panel Outside 90° Corner Systems
• Effective Date: 01-May-2008

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 – 02a (Reapproved 2008)
Standard Specification for
Stainless Steel Socket Button and Flat Countersunk Head
Cap Screws
ThisstandardisissuedunderthefixeddesignationF879;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) 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. Scope Stainless Steel Parts, Equipment, and Systems
A555/A555M Specification for General Requirements for
1.1 This specification covers the chemical and mechanical
Stainless Steel Wire and Wire Rods
requirements for stainless steel inch hexagon socket button
A751 Test Methods, Practices, andTerminology for Chemi-
(SBHCS) and flat countersunk (SFHCS) head cap screws with
cal Analysis of Steel Products
nominal thread 0.060 through 0.625 in. intended for use in
A967 Specification for Chemical Passivation Treatments
applications requiring general corrosion resistance.
for Stainless Steel Parts
1.2 The following three conditions are covered:
D3951 Practice for Commercial Packaging
1.2.1 Austenitic alloy group 1 AF in an annealed condition
E18 Test Methods for Rockwell Hardness of Metallic Ma-
at 85 ksi maximum,
terials
1.2.2 Austenitic alloy group 1 CW in a cold-worked condi-
E92 Test Method for Vickers Hardness of Metallic Materi-
tion at 80 ksi minimum, and
als
1.2.3 Austenitic alloy group 1 condition CW1 in a cold
E384 Test Method for Microindentation Hardness of Mate-
worked condition at 102 ksi minimum.
rials
1.3 Units—The values stated in inch-pound units are to be
F593 Specification for Stainless Steel Bolts, Hex Cap
regarded as standard. No other units of measurement are
Screws, and Studs
included in this standard.
F606 Test Methods for Determining the Mechanical Prop-
1.4 The following precautionary caveat pertains only to the
erties of Externally and Internally Threaded Fasteners,
test method portion, Section 12, of this specification: This
Washers, Direct Tension Indicators, and Rivets
standard does not purport to address all of the safety concerns,
F788/F788M Specification for Surface Discontinuities of
if any, associated with its use. It is the responsibility of the user
Bolts, Screws, and Studs, Inch and Metric Series
of this standard to establish appropriate safety and health
F1470 Practice for Fastener Sampling for Specified Me-
practices and determine the applicability of regulatory limita-
chanical Properties and Performance Inspection
tions prior to use.
2.2 ASME Standard:
2. Referenced Documents B 18.3 Socket Cap, Shoulder and Set Screws (Inch Series)
2.1 ASTM Standards:
3. Classification
A262 Practices for Detecting Susceptibility to Intergranular
3.1 The designation of the alloy group and condition of this
Attack in Austenitic Stainless Steels
specification shall be consistent with the stainless steel desig-
A342/A342M Test Methods for Permeability of Feebly
nations in Specification F593.
Magnetic Materials
3.2 The austenitic stainless steel socket screw shall be
A380 Practice for Cleaning, Descaling, and Passivation of
designated F879 Group 1 Condition AF, F879 Group 1
Condition CW, or F879 Group 1 Condition CW1.
This specification is under the jurisdiction of ASTM Committee F16 on
4. Ordering Information
Fasteners and is the direct responsibility of Subcommittee F16.04 on Nonferrous
Fasteners.
4.1 Orders for material under this specification shall include
Current edition approved May 1, 2008. Published August 2008. Originally
the following information:
approved in 1986. Last previous edition approved in 2002 as F879 – 02a. DOI:
10.1520/F0879-02AR08.
4.1.1 Quantity (number of pieces of each item).
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 Available from Global Engineering Documents, 15 Inverness Way, East
the ASTM website. Englewood, CO 80112-5704, http://www.global.ihs.com.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F879 – 02a (2008)
4.1.2 Name of the screw, SBHCS or SFHCS. 7. Mechanical Properties
4.1.3 Dimensions, including nominal thread designation,
7.1 The finished screws shall conform to the mechanical
thread pitch, and nominal screw length (inches). A standard
requirements specified in Table 1.
part number may be used for this definition.
7.2 Screws having a nominal length equal to or greater than
4.1.4 Alloy group and condition (Group 1AF, Group 1 CW,
three diameters shall be tensile tested full size and shall meet
Group 1 CW1).
the full size breaking strength requirements specified in Table
4.1.5 Certification, if required (see Section 15).
3. Tensile failures through the head are acceptable providing
4.1.6 ASTM specification and year of issue.
the load requirements are satisfied.
4.1.7 Any special or supplemental requirements (see
7.3 Screws that are too short (lengths less than specified in
Supplementary Requirements S1 through S6).
7.2 or that have insufficient threads for tension testing) shall
not be subject to tension tests, but shall conform to the
5. Materials and Manufacture
hardness requirements of Table 1.
5.1 Screws shall be formed by upsetting or extruding, or
8. Corrosion Resistance Requirements Corrosion Resistance
both.
Requirements
5.2 Screws shall be roll threaded.
8.1 Carbide Precipitation:
5.3 Heat Treatment—Austenitic alloys Condition AF
8.1.1 Rod, bar, and wire in the austenitic alloy group 1 used
screws, following manufacture, shall be annealed by heating to
to make fasteners in accordance with this specification shall be
1900 6 50°F to obtain maximum corrosion resistance and
capable of passing the test for susceptibility to intergranular
minimumpermeability.Thescrewsshallbeheldforasufficient
corrosion as specified in Practice E of Practices A262.
time at temperature, then cooled at a rate sufficient to prevent
8.1.2 AsstatedinPracticesA262,samplesmaybesubjected
precipitationofthecarbideandprovidethepropertiesspecified
to the faster and more severe screening test in accordance with
in Table 1.
Practice A. Failing Practice A, specimens shall be tested to
5.4 When Condition CW or CW1 is specified, the austenitic
Practice E and be considered satisfactory if passing Practice E.
alloys shall be annealed as specified in 5.3, generally by the
raw material manufacturer, then cold worked to develop
9. Dimensions
specific properties.
9.1 Unless otherwise specified, the dimensions shall con-
form to the requirements of ASME B 18.3.
6. Chemical Composition
10. Workmanship and Finish
6.1 It is the intent of this specification that screws shall be
ordered by alloy condition. The chemical composition of the 10.1 Surface Treatment—Unless otherwise specified,
screws shall conform to the requirements of Table 2. screwsshallbecleaned,descaled,andpassivatedinaccordance
6.2 Unless otherwise specified in the inquiry and purchase with Practice A380 or Specification A967 at the option of the
order (see Supplementary Requirement S2), the choice of
manufacturer.
stainless steel used shall be that of the fastener manufacturer as 10.2 Surface Discontinuities:
determined by his fabrication methods and material availabil- 10.2.1 The surface discontinuities for these products shall
ity. The specific stainless steel used by the manufacturer shall conform to Specification F788/F788M and the additional
beclearlyidentifiedonallcertificationrequiredinthepurchase limitations specified herein.
order and shall have a chemical composition conforming to the 10.2.1.1 Forging defects that connect the socket to the
limits specified in Table 2. periphery of the head are not permissible. Defects originating
6.3 When chemical analysis is performed by the purchaser on the periphery and with a traverse indicating a potential to
using finished fasteners, the chemical composition obtained intersect are not permissible. Other forging defects are permis-
shall conform to the limits specified in Table 2 for the specific sible provided those located in the bearing area, fillet, and top
alloy. Chemical composition shall conform to the tolerances surfaces shall not have a depth exceeding 0.03 D or 0.005 in.
specified in Specification A555/A555M. whichever is greater. For peripheral discontinuities, the maxi-
6.3.1 In the event of a discrepancy, a referee analysis of the mum depth may be 0.06 D (see Fig. 1).
samples for each lot as specified in 12.1 shall be made in 10.2.1.2 Forging defects located in the socket wall within
accordance with 11.3.1. 0.1 times the actual key engagement, T, from the bottom of the
TABLE 1 Mechanical Property Requirements
A B
Full Size Product Tests Machined Specimen Tests Core Hardness
Alloy
C
Tensile Extension Tensile Yield Elongation
Condition Vickers Rockwell
Strength ksi min Strength ksi Strength ksi %min
AF 85 max 0.6D 85 max 55 max 40 210 max 95 HRB max
CW 80 min 0.4D 80 min 40 min 25 150 min 50 HRA min
CW1 102 min 0.4D 87 min 65 min 20 220 min 59 HRA min
A
Actual full-size testing of condition CW and CW1 may result in decreased tensile strength because of the head configuration (seeTable 3). For fasteners with nominal
thread diameters larger than 0.625 in., the mechanical properties shall be agreed upon between the user and manufacturer.
B
Core hardness is only required when full-size product testing cannot be accomplished.
C
D denotes nominal thread size.
F879 – 02a (2008)
TABLE 2 Alloy Group 1 Chemical Requirements
Composition, % maximum except as shown
UNS
Alloy Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Copper Molybdeneunm
Designation
Austenitic Alloys
S30400 304 0.08 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 10.5 1.00 . . .
S30403 304L 0.030 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 12.0 1.00 . . .
S30500 305 0.12 2.00 0.045 0.030 1.00 17.0 to 19.0 10.5 to 13.0 1.00 . . .
S38400 384 0.08 2.00 0.045 0.030 1.00 15.0 to 17.0 17.0 to 19.0 . . . . . .
S30430 18–9LW 0.10 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.0 to 4.0 . . .
S30433 302HQ 0.03 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.0 to 4.0 . . .
S31600 316 0.08 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.00 to 3.0
S31603 316L 0.03 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.00 to 3.0
TABLE 3 Breaking Strength Values for Full Size Fasteners
NOTE 1—Breaking loads are based on tensile stress area and strengths
of 85 ksi max (AF), 64 ksi min (CW), and 82 ksi for CW1. The minimum
loads for the CW and CW1 conditions are based on the tensile properties
of 80 ksi minimum material strength and 102 ksi minimum material
strength, respectively, reduced by 20 % to allow for the head critical
nature of these configurations. See Note A in Table 1. Actual strength of
the threaded section, if size permits, may be determined by removing the
head and testing the threaded section as a stud.
Alloy Condition, lb. min
Tensile Stress
Nominal Size
Area, in.
AF CW CW1
0 0.060–80 0.00180 153 115 147
1 0.073–64 0.00263 223 168 215
2 0.086–56 0.00370 314 237 303
3 0.099–48 0.00487 414 312 399
4 0.112–40 0.00604 513 386 495
5 0.125–40 0.00796 676 509 652
6 0.138–32 0.00909 772 581 745
8 0.164–32 0.0140 1191 897 1149
10 0.190–24 0.0175 1490 1122 1438
⁄4 0.250–20 0.0318 2705 2037 2609
⁄16 0.312–18 0.0524 4457 3356 4299
⁄8 0.375–16 0.0775 6587 4959 6354
⁄2 0.500–13 0.1419 12 061 9082 11 636
⁄8 0.625–11 0.226 19 210 14 464 18 532
FIG. 1 Head Discontinuities (See 10.2.1)
socketarenotpermissible.Discontinuitieslocatedelsewherein
the socket shall not have a length exceeding 0.25 T,ora
maximum depth of 0.03 D not to exceed 0.005 in. (see Fig. 2).
10.2.1.3 Seamsintheshankshallnotexceedadepthof0.03
D or 0.008 in. whichever is greater.
10.2.1.4 No transverse discontinuities shall be permitted in
the head-to-shank fillet area.
10.2.1.5 Threads shall have no laps at the root or on the
flanks, as shown in Fig. 3. Laps are permitted at the crests (Fig.
3(C)) that do not exceed 25 % of the basic thread depth, and on
the flanks outside the pitch cylinder. Longitudinal seams rolled
FIG. 2 Socket Discontinuities (See 10.2.1)
beneath the root of the thread and across the crests of the
threads are acceptable within the limits of 10.2.1.3.
conforms to the specified requirements. Additional tests of
11. Number of Tests
individual shipments of fasteners are not ordinarily necessary.
11.1 The requirements of this specification shall be met in A record of the individual heat of steel in each lot shall be
continuous mass production for stock and the manufacturer maintained. The containers shall be coded to permit identifi-
cation of the lot.
shall make sample inspections to ensure that the product
F879 – 02a (2008)
FIG. 3 Thread Discontinuities
11.2 When specified in the purchase order, the manufacturer 11.4.2 Products that have been hot worked shall be solution
shall furnish a test report of the last complete set of chemical annealed and tested to determine freedom from precipitated
analysis and mechanical tests for each stock size in each carbides. Not less than one corrosion test shall be made from
shipment. each lot. Corrosion tests shall be performed in accordance with
11.3 When tests of individual shipments are required, Practices A262, Practices A or E as applicable.
Supplementary Requirement S1 must be specified in the
inquiry and order.
12. Test Methods
11.3.1 When the purchaser does not specify the sampling
12.1 Chemical Analysis—The chemical composition shall
plan and basis of acceptance, the following shall apply:
be determined in accordance with Test Method A751.
11.3.1.1 The lot, for purposes of selecting samples, shall
12.1.1 The fastener manufacturer may accept the chemical
consist of all products offered for inspection and testing at one
analysisofeachheatofrawmaterialpurchasedandreportedon
time that are of the same type, style, nominal diameter, thread
the raw material certification furnished by the raw material
pitch, nominal length, material, condition, and surface finish.
producer. The fastener manufacturer is not required to do any
11.3.1.2 From each lot, samples shall be selected at random
further chemical analysis testing provided that precise heat lot
and tested for each requirement in accordance with the
traceability has been maintained throughout the manufacturing
following:
process on each lot of fasteners produced and delivered.
Number of Pieces in Lot Number of Samples
12.2 Mechanical Tests:
800 an
...

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:F 879–02 Designation: F 879 – 02a (Reapproved 2008)
Standard Specification for
Stainless Steel Socket Button and Flat Countersunk Head
Cap Screws
This standard is issued under the fixed designation F 879; 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 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.
1.2The following two conditions are covered:
1.2.1Austenitic alloy condition AF in an annealed condition at 85 ksi maximum and
1.2.2Austenitic alloy condition CW in a cold-worked condition at 95 ksi minimum.
1.3
1.2 The following three conditions are covered:
1.2.1 Austenitic alloy group 1 AF in an annealed condition at 85 ksi maximum,
1.2.2 Austenitic alloy group 1 CW in a cold-worked condition at 80 ksi minimum, and
1.2.3 Austenitic alloy group 1 condition CW1 in a cold worked condition at 102 ksi minimum.
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 and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
A 262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
A342 342/A 342M Test Methods for Permeability of Feebly Magnetic Materials
A 380 Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems
A 555/A 555M Specification for General Requirements for Stainless Steel Wire and Wire Rods
A 751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
A 967 Specification for Chemical Passivation Treatments for Stainless Steel Parts
D 3951 Practice for Commercial Packaging
E 18 Test Methods for Rockwell Hardness of Metallic Materials
E 92 Test Method for Vickers Hardness of Metallic Materials
E 384 Test Method for Microindentation Hardness of Materials
F 593 Specification for Stainless Steel Bolts, Hex Cap,Cap Screws, and Studs
F 606 Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers,
Direct Tension Indicators, and Rivets
F 788/F 788M Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series
F 1470 Guide for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
2.2 ASME Standard:
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 June 10, 2002. Published June 2002. Originally published as F879–86. Last previous edition F879–01.
Current edition approved May 1, 2008. Published August 2008. Originally approved in 1986. Last previous edition approved in 2002 as F 879 – 02a.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
, Vol 01.03.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.
F 879 – 02a (2008)
B 18.3 Socket Cap, Shoulder and Set Screws (Inch Series)
3. Classification
3.1 The designation of the alloy group and condition of this specification shall be consistent with the stainless steel designations
in Specification F 593.
3.2 The austenitic stainless steel socket screw shall be designated F 879 Group 1 ConditionAF orAF, F 879 Group 1 Condition
CW, or F879 Group 1 Condition CW1.
4. Ordering Information
4.1 Orders for material under this specification shall include the following information:
4.1.1 Quantity (number of pieces of each item).
4.1.2 Name of the screw, SBHCS or SFHCS.
4.1.3 Dimensions, including nominal thread designation, thread pitch, and nominal screw length (inches). A standard part
number may be used for this definition.
4.1.4Alloy group, and condition (Group 1 AF or Group 1 CW).
4.1.4 Alloy group and condition (Group 1 AF, Group 1 CW, Group 1 CW1).
4.1.5 Certification, if required (see Section 15).
4.1.6 ASTM specification and year of issue.
4.1.7 Any special or supplemental requirements (see Supplementary Requirements S1 through S6).
5. Materials and Manufacture
5.1 Screws shall be formed by upsetting or extruding, or both.
5.2 Screws shall be roll threaded.
5.3 Heat Treatment—Austenitic alloys Condition AF screws, following manufacture, shall be annealed by heating to 1900 6
50°F 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 in Table 1.
5.4 When Condition CW or CW1 is specified, the austenitic alloys shall be annealed as specified in 5.3, generally by the raw
material manufacturer, then cold worked to develop specific properties.
6. Chemical Composition
6.1 It is the intent of this specification that screws shall be ordered by alloy condition. The chemical composition of the screws
shall conform to the requirements of Table 2.
6.2 Unless otherwise specified in the inquiry and purchase order (see Supplementary Requirement S2) when CW or AF
condition property class is specified,S2), the choice of stainless steel used shall be that of the fastener manufacturer as determined
by his fabrication methods and material availability.The specific stainless steel used by the manufacturer shall be clearly identified
on all certification required in the purchase order and shall have a chemical composition conforming to the limits specified inTable
2.
6.3 When chemical analysis is performed by the purchaser using finished fasteners, the chemical composition obtained shall
conform to the limits specified in Table 2 for the specific alloy. Chemical composition shall conform to the tolerances specified
in Specification A 555.
Annual Book of ASTM Standards, Vol 03.04.
Available from Global Engineering Documents, 15 Inverness Way, East Englewood, CO 80112-5704, http://www.global.ihs.com.
TABLE 1 Mechanical Property Requirements
A
Alloy Full Size Product Tests Machined Specimen Tests Hardness
B
Condition
Vickers RCockwrell Hardness
Tensile Extension Tensile Yield Elongation
min max min max
Strength ksi min Strength ksi Strength ksi %min
C
Tensile Extension Tensile Yield Elongation
Vickers max min maxRockwell
Strength ksi min Strength ksi Strength ksi %min
AF 85 max 0.6D 80 max 50 max 40 . 170 .
AF 85 max 0.6D 80 max 55 max 40 210 max 170 .
CW 90 min 0.4D 85 min 58 min 20 220 330 HRA min
CW 90 min 0.4D 85 min 40 min 25 150 min 50 HRA min
CW1 B80 C330.4D 87 min 65 min 20 220 min 59 HRA min
CW1 B80 0.4D 87 min 65 min 20 220 min 59 HRA min
A
Actual full-size testing of condition CW and CW1 may result in decreased tensile strength because of the head configuration (seeTable 3). For fasteners with nominal
thread diameters larger than 0.625 in., the mechanical properties shall be agreed upon between the user and manufacturer.
B
Core hardness is only required when full-size product testing cannot be accomplished.
C
D denotes nominal thread size.
F 879 – 02a (2008)
TABLE 2 Alloy Group 1 Chemical Requirements
Composition, % maximum except as shown
UNS
Alloy Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Copper Molybdeneunm
Designation
Austenitic Alloys
S30400 304 0.08 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 10.5 1.00
S30400 304 0.08 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 10.5 1.00 .
S30403 304L 0.030 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 12.0 1.00
S30403 304L 0.030 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 12.0 1.00 .
S30500 305 0.12 2.00 0.045 0.030 1.00 17.0 to 19.0 10.5 to 13.0 1.00
S30500 305 0.12 2.00 0.045 0.030 1.00 17.0 to 19.0 10.5 to 13.0 1.00 .
S38400 384 0.08 2.00 0.045 0.030 1.00 15.0 to 17.0 17.0 to 19.0 .
S38400 384 0.08 2.00 0.045 0.030 1.00 15.0 to 17.0 17.0 to 19.0 . .
S30430 18–9LW 0.10 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.0to4.0
S30430 18–9LW 0.10 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.0to4.0 .
S30433 302HQ 0.03 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.0to4.0
S30433 302HQ 0.03 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.0to4.0 .
S31600 316 0.08 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 .
S31600 316 0.08 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . 2.00 to 3.0
S31603 316L 0.03 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.00 to 3.0
6.3.1 Intheeventofadiscrepancy,arefereeanalysisofthesamplesforeachlotasspecifiedin12.1shallbemadeinaccordance
with 11.3.1.
7. Mechanical Properties
7.1 The finished screws shall conform to the mechanical requirements specified in Table 1.
7.2 Screws having a nominal length equal to or greater than three diameters shall be tensile tested full size and shall meet the
full size breaking strength requirements specified in Table 3. Tensile failures through the head are acceptable providing the load
requirements are satisfied.
7.3 Screws that are too short (lengths less than specified in 7.2 or that have insufficient threads for tension testing) shall not be
subject to tension tests, but shall conform to the maximum and minimum hardness requirements of Table 1.
8. Corrosion Resistance Requirements Corrosion Resistance Requirements
8.1 Carbide Precipitation:
8.1.1 Rod, bar, and wire in the austenitic alloy group 1 used to make fasteners in accordance with this specification shall be
capable of passing the test for susceptibility to intergranular corrosion as specified in Practice E of Practices A 262.
TABLE 3 Breaking Strength Values for Full Size Fasteners
NOTE 1—Breaking loads are based on tensile stress area and strengths
of 85 ksi max (AF) and 76 ksi min (CW). The minimum loads for CW
condition are based on the tensile properties of 95 ksi material strength,
reduced by 20 % to allow for the head critical nature of these configura-
tions.Table 1.Actual strength of the threaded section, if size permits, may
be determined by removing the head and testing the threaded section as a
stud.
Alloy Condition, lb. min
Tensile Stress
Nominal Size
Area, in.
AF, lb, max CW, lb, min CW1
0 0.060–80 0.00180 153 137 147
1 0.073–64 0.00263 224 200 215
2 0.086–56 0.00370 255 280 303
3 0.099–48 0.00487 414 370 399
4 0.112–40 0.00604 513 460 495
5 0.125–44 0.00796 676 600 652
5 0.125–40 0.00796 676 600 652
6 0.138–32 0.00909 772 690 745
8 0.164–32 0.0140 1190 1060 1149
10 0.190–24 0.0175 1487 1330 1438
⁄4 0.250–20 0.0318 2703 2420 2609
⁄16 0.312–18 0.0524 4454 3980 4299
⁄8 0.375–16 0.0775 6588 5890 6354
⁄2 0.500–13 0.1419 12 061 10 8002 11 636
⁄2 0.500–13 0.1419 12 061 9082 11 636
⁄8 0.625–11 0.226 19 210 17 464 18 53200
⁄8 0.625–11 0.226 19 210 14 464 18 532
F 879 – 02a (2008)
8.1.2 As stated in Practices A 262, samples may be subjected to the faster and more severe screening test in accordance with
Practice A. Failing Practice A, specimens shall be tested to Practice E and be considered satisfactory if passing Practice E.
9. Dimensions
9.1 Unless otherwise specified, the dimensions shall conform to the requirements of ASME B18.3.
10. Workmanship and Finish
10.1 Surface Treatment—Unless otherwise specified, screws shall be cleaned, descaled, and passivated in accordance with
Practice A 380 or Specification A 967 at the option of the manufacturer.
10.2 Surface Discontinuities:
10.2.1 The surface discontinuities for these products shall conform to Specification F 788/F 788M and the additional limitations
specified herein.
10.2.1.1 Forging defects that connect the socket to the periphery of the head are not permissible. Defects originating on the
periphery and with a traverse indicating a potential to intersect are not permissible. Other forging defects are permissible provided
those located in the bearing area, fillet, and top surfaces shall not have a depth exceeding 0.03 D or 0.005 in. whichever is greater.
For peripheral discontinuities, the maximum depth may be 0.06 D (see Fig. 1).
10.2.1.2 Forging defects located in the socket wall within 0.1 times the actual key engagement, T, from the bottom of the socket
are not permissible. Discontinuities located elsewhere in the socket shall not have a length exceeding 0.25 T, or a maximum depth
of 0.03 D not to exceed 0.005 in. (see Fig. 2).
10.2.1.3 Seams in the shank shall not exceed a depth of 0.03 D or 0.008 in. whichever is greater.
10.2.1.4 No transverse discontinuities shall be permitted in the head-to-shank fillet area.
10.2.1.5 Threads shall have no laps at the root or on the flanks, as shown in Fig. 3. Laps are permitted at the crests (Fig. 3(C))
that do not exceed 25 % of the basic thread depth, and on the flanks outside the pitch cylinder. Longitudinal seams rolled beneath
the root of the thread and across the crests of the threads are acceptable within the limits of 10.2.1.3.
11. Number of Tests
11.1 The requirements of this specification shall be met in continuous mass production for stock and the manufacturer shall
makesampleinspectionstoensurethattheproductconformstothespecifiedrequirements.Additionaltestsofindividualshipments
of fasteners are not ordinarily necessary. A record of the individual heat of steel in each lot shall be maintained. The containers
shall be coded to permit identification of the lot.
11.2 When specified in the purchase order, the manufacturer shall furnish a test report of the last complete set of chemical
analysis and mechanical tests for each stock size in each shipment.
11.3
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