ASTM F837-13(2018)
(Specification)Standard Specification for Stainless Steel Socket Head Cap Screws
Standard Specification for Stainless Steel Socket Head Cap Screws
ABSTRACT
This specification covers stainless steel metric socket head cap screws (SHCS) intended for use in applications requiring general corrosion resistance. Two groups of stainless steel alloys are covered, austenitic Grade A1 and martensitic Grade C1. Four property classes are covered: austenitic A1-50 in an annealed condition; austenitic A1-55 in a cold worked condition; austenitic A1-70 in a cold worked condition, and martensitic C1-110 in a heat treated condition. Materials shall be tested and the individual grades shall conform to forging; threads; heat treatment; chemical composition; mechanical properties such as thread diameter, tensile strength, yield strength, elongation, core hardness (Vickers and Rockwell); and corrosion resistance values. Workmanship, finish, and appearance are also detailed.
SCOPE
1.1 This specification covers the chemical and mechanical requirements for stainless steel inch socket head cap screw (SHCS) with nominal thread 0.060 through 1.500 in. and intended for use in applications requiring general corrosion resistance.
1.2 Three groups of stainless steel alloys are covered, austenitic Group 1 and 2 and martensitic Group 5.
1.3 Four property conditions are covered: austenitic Alloy Groups 1 and 2 in an annealed condition (AF) at 85 ksi maximum, in two cold worked conditions (CW) at 80 ksi minimum, (CW1) at 102 ksi minimum, and martensitic Alloy Group 5 in a heat treated condition (HT) at 160 ksi minimum.
1.4 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 The following precautionary caveat pertains only to the test method portion, Section 13, 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.
1.6 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.
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Designation:F837 −13 (Reapproved 2018)
Standard Specification for
Stainless Steel Socket Head Cap Screws
ThisstandardisissuedunderthefixeddesignationF837;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
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. Referenced Documents
2.1 ASTM Standards:
1.1 This specification covers the chemical and mechanical
A262Practices for Detecting Susceptibility to Intergranular
requirements for stainless steel inch socket head cap screw
Attack in Austenitic Stainless Steels
(SHCS) with nominal thread 0.060 through 1.500 in. and
A342/A342MTest Methods for Permeability of Weakly
intended for use in applications requiring general corrosion
Magnetic Materials
resistance.
A380Practice for Cleaning, Descaling, and Passivation of
1.2 Three groups of stainless steel alloys are covered,
Stainless Steel Parts, Equipment, and Systems
austenitic Group 1 and 2 and martensitic Group 5.
A555/A555MSpecification for General Requirements for
Stainless Steel Wire and Wire Rods
1.3 Four property conditions are covered: austenitic Alloy
A751Test Methods, Practices, and Terminology for Chemi-
Groups 1 and 2 in an annealed condition (AF) at 85 ksi
cal Analysis of Steel Products
maximum, in two cold worked conditions (CW) at 80 ksi
A967Specification for Chemical PassivationTreatments for
minimum, (CW1) at 102 ksi minimum, and martensitic Alloy
Stainless Steel Parts
Group 5 in a heat treated condition (HT) at 160 ksi minimum.
D3951Practice for Commercial Packaging
E18Test Methods for Rockwell Hardness of Metallic Ma-
1.4 Thevaluesstatedininch-poundunitsaretoberegarded
terials
asstandard.Nootherunitsofmeasurementareincludedinthis
E92Test Methods for Vickers Hardness and Knoop Hard-
standard.
ness of Metallic Materials
1.5 The following precautionary caveat pertains only to the
E384Test Method for Microindentation Hardness of Mate-
test method portion, Section 13, of this specification: This
rials
standard does not purport to address all of the safety concerns,
F606Test Methods for Determining the Mechanical Proper-
if any, associated with its use. It is the responsibility of the user
ties of Externally and Internally Threaded Fasteners,
of this standard to establish appropriate safety, health, and
Washers, and Rivets (Metric) F0606_F0606M
environmental practices and determine the applicability of
F788/F788MSpecification for Surface Discontinuities of
regulatory limitations prior to use.
Bolts, Screws, and Studs, Inch and Metric Series
F1470Practice for Fastener Sampling for Specified Me-
1.6 This international standard was developed in accor-
chanical Properties and Performance Inspection
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
2.2 ASME Standard:
Development of International Standards, Guides and Recom- ASME B18.3Socket Cap, Shoulder, and Set Screws—Inch
mendations issued by the World Trade Organization Technical Series
Barriers to Trade (TBT) Committee.
2.3 JIS Standard:
JIS G 4311Heat Resisting Steel Bar and Wire Rods
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 standard’s Document Summary page on
This specification is under the jurisdiction of ASTM Committee F16 on the ASTM website.
Fasteners and is the direct responsibility of Subcommittee F16.04 on Nonferrous Available from American Society of Mechanical Engineers (ASME), ASME
Fasteners. International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
Current edition approved Sept. 1, 2018. Published September 2018. Originally www.asme.org.
ɛ1 4
approved in 1988. Last previous edition approved in 2013 as F837–13 . DOI: AvailablefromJapaneseStandardsAssociation(JSA),MitaMTBldg.,3-13-12
10.1520/F0837-13R18. Mita, Minato-ku, Tokyo 108-0073, Japan, http://www.jsa.or.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
F837−13 (2018)
3. Classification 5.2 Threads—Unlessotherwisespecified,screwsinsizesup
to 1.00 in. inclusive and product lengths up to 6 in. inclusive,
3.1 Theausteniticstainlesssteelsocketheadcapscrewshall
shall have threads formed by rolling, except by special agree-
be designated F837 Group 1 or 2 ConditionAF, F837 Group 1
mentwiththepurchaser.Largerproductsmayberolled,cut,or
or 2 Condition CW, or F837 Group 1 or 2 Condition CW1.
ground at the option of the manufacturer.
3.2 The martensitic stainless steel socket head cap screw
shall be designated F837 Group 5 Condition HT.
6. Heat Treatment
6.1 Austenitic alloys Group 1 or 2 Condition AF screws,
4. Ordering Information
followingmanufacture,shallbeannealedbyheatingto1900 6
4.1 Orders for socket head cap screws under this specifica-
50°F to obtain maximum corrosion resistance and minimum
tion shall include:
permeability. The screws shall be held for a sufficient time at
4.1.1 Quantity (number of pieces of each item).
temperature and then cooled at a rate sufficient to prevent
4.1.2 Name of the item (socket head cap screws, SHCS).
precipitation of the carbide and to provide the properties
4.1.3 Size (nominal diameter, thread pitch, thread class,
specified in Table 1.
screw length) or part number.
6.2 WhenConditionCWorCW1isspecified,theaustenitic
4.1.4 Alloy Group (see 7.1) and Condition (Group 1 or 2
alloysshallbeannealedasspecifiedin6.1generallybytheraw
AF, Group 1 or 2 CW, Group 1 or 2 CW1, or Group 5 HT).
material manufacturer, then cold worked to develop specific
4.1.5 ASTM specification and year of issue. When year of
properties.
issue is not specified, fasteners shall be furnished to the latest
issue.
6.3 MartensiticalloyGroup5ConditionHTscrewsshallbe
4.1.6 Supplementary requirements, if any, (see S1 through
hardened and tempered by heating to 1800 6 50°F sufficient
S7).
for austenitization, holding for at least ⁄2 h, rapid air or oil
4.1.7 Additionalspecialrequirements,ifany,tobespecified
quenching, reheating to 525°F minimum and holding for at
on the purchase order:
least1handthenaircoolingtoprovidethepropertiesspecified
4.1.7.1 Forming (see 5.1).
in Table 1.
4.1.7.2 Threading (see 5.2).
4.1.7.3 Surface finish (see 11.1).
7. Chemical Properties
4.1.7.4 Alloy selection (see 7.2).
7.1 It is the intent of this specification that screws shall be
4.1.7.5 Test report (see 12.2).
ordered by alloy group and condition. The chemical composi-
4.1.7.6 Additional testing (see 12.3).
tion of the screw material shall conform to the requirements of
4.1.7.7 Inspection (see 14.1).
Table 2.
4.1.7.8 Rejection (see 15.1).
7.2 Unless otherwise specified in the inquiry and purchase
4.1.7.9 Certification (see 16.1).
order (see Supplementary Requirements S2) the choice of an
4.1.7.10 Special packaging requirements (see 18.3).
alloy from within a group shall be at the discretion of the
4.1.7.11 Supplementary requirements as needed.
fastener manufacturer as required by their method of fastener
5. Materials and Manufacture fabricationandmaterialavailability.Thespecificalloyusedby
the manufacturer shall be clearly identified on all certification
5.1 Heads—Unless otherwise specified the head and socket
required in the purchase order and shall have chemical com-
recess of the screw may be hot forged, cold forged, or
position conforming to the limits specified in Table 2.
machined at the option of the manufacturer. Users requiring
coldforgedheadsshouldspecifySupplementaryRequirements 7.3 When chemical analysis is performed by the purchaser
S6. using finished fasteners representing each lot, the chemical
TABLE 1 Mechanical Property Requirements
B
Full-Size Product Machine Specimen Core Hardness
Alloy
Nominal
Alloy Mechanical
Minimum
Condition Thread
Tensile Minimum Tensile Yield Strength,
Group Property
A
Elongation, Vickers Rockwell
C
Diameter
Strength, ksi Extension Strength, ksi ksi
Marking
%
1 AF F837A 0.060–1.500 85 max 0.6D 85 max 55 max 40 210 max 95 HRB max
1 CW F837B 0.060–0.750 80 min 0.4D 80 min 40 min 25 150 min 50 HRA min
1 CW1 F837C 0.060–0.750 102 min 0.4D 87 min 65 min 20 220 min 59 HRA min
2 AF F837D 0.060–1.500 85 max 0.6D 85 max 55 max 40 210 max 95 HRB max
2 CW F837E 0.060–0.750 80 min 0.4D 80 min 40 min 25 150 min 50 HRA min
2 CW1 F837F 0.060–0.750 102 min 0.4D 87 min 65 min 20 220 min 59 HRA min
5 HT F837G 0.060–0.190 180 min . . . . . . . . . . . . 350–423 36–43 HRC
5 HT F837H 0.250–1.500 180 min 0.2D 160 min 120 min 12 350–423 36–43 HRC
A
For CW and CW1 condition fasteners with nominal thread diameter larger than 0.750 in., the mechanical properties and marking shall be agreed upon between the user
and manufacturer.
B
Core hardness is only required when full-size product tensile testing cannot be accomplished.
C
D denotes nominal thread size.
F837−13 (2018)
TABLE 2 Chemical Requirements
Composition, % maximum except as shown
Alloy UNS
Alloy
Phosphorus
Group Designation
Carbon Manganese Sulfur Silicon Chromium Nickel Copper Molybdenum
Austenitic Alloys
A B
1 S30300 303 0.15 2.00 0.20 0.15 min 1.00 17.0 to 19.0 8.0 to 10.0 . . . 0.60 max
1 S30400 304 0.08 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 10.5 1.00 . . .
1 S30403 304L 0.030 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 12.0 1.00 . . .
1 S30500 305 0.12 2.00 0.045 0.030 1.00 17.0 to 19.0 10.5 to 13.0 1.00 . . .
1 S38400 384 0.08 2.00 0.045 0.030 1.00 15.0 to 17.0 17.0 to 19.0 . . . . . .
A B
1 S20300 XM1 0.08 5.0 to 6.5 0.040 0.18 to 0.35 1.00 16.0 to 18.0 5.0 to 6.5 1.75 to 2.25 0.50 max
1 S30430 18-9LW 0.10 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.00 to 4.00 . . .
1 S30433 302HQ 0.03 2.00 0.045 0.030 4.00 17.0 to 19.0 8.0 to 10.0 3.0 to 4.0 . . .
C
1 . 304J3 0.08 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.5 1.00 to 3.00 .
2 S31600 316 0.08 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.0 to 3.0
2 S31603 316L 0.03 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.0 to 3.0
Martensitic Alloys
5 UNS41000 410 0.15 1.00 0.040 0.030 1.00 11.5 to 13.5 . . .
A
Free machining grades are not recommended for forged product. These grades may be furnished only when approved by the purchaser.
B
At manufacturer’s option, determined only when intentionally added.
C
304J3 from JIS standard G 4311.
contentsobtainedshallconformtothelimitsspecifiedinTable 10. Dimensions
2 for the specific alloy. Chemical contents shall conform to the
10.1 Unless otherwise specified, the products shall conform
tolerances specified in Specification A555/A555M.
to the requirements of ASME B18.3.
7.3.1 In the event of discrepancy, a referee analysis as
specified in 13.1 of samples for each lot shall be made in
11. Workmanship, Finish, and Appearance
accordance with 12.3.1.
11.1 Surface Treatment—Unlessotherwisespecified,screws
8. Mechanical Properties
shall be cleaned, descaled and passivated in accordance with
Practice A380 or Specification A967 at the option of the
8.1 Screws shall be tested in accordance with the mechani-
manufacturer.
cal testing requirements for the alloy group and condition
nominal thread diameter, length, and specified minimum ten-
11.2 The surface discontinuities for these products shall
sile strength as specified in Table 3 and shall meet the
conform to Specification F788/F788M and the additional
mechanical requirements specified for that product in Table 1.
limitations specified herein.
11.2.1 Forgingdefectsthatconnectthesockettotheperiph-
8.2 For products on which both hardness and tension tests
ery of the head are not permissible. Defects originating on the
are performed, acceptance based on tensile requirements shall
periphery and with a traverse indicating a potential to intersect
take precedence over low hardness readings (see Table 4).
are not permissible. Other forging defects are permissible
9. Corrosion Resistance
provided those located in the bearing area, fillet, and top
surfaces shall not have a depth exceeding 0.03 D or 0.005 in,
9.1 Carbide Precipitation:
whichever is greater. For peripheral discontinuities, the maxi-
9.1.1 Rod, bar, and wire in the austenitic alloy groups 1 and
mum depth may be 0.06 D (see Fig. 1).
2 (not including the free-machining grade 303) used to make
11.2.2 Forging defects located in the socket wall within 0.1
fasteners in accordance with this specification shall be capable
times the actual key engagement, T, from the bottom of the
of passing the test for susceptibility to intergranular corrosion
socketarenotpermissible.Discontinuitieslocatedelsewherein
as specified in Practice E of Practice A262.
the socket shall not have a length exceeding 0.25 T,ora
9.1.2 AsstatedinPracticesA262,samplesmaybesubjected
maximum depth of 0.03 D not to exceed 0.005 in. (see Fig. 2).
to the faster and more severe screening test in accordance with
Practice A. Failing Practice A, specimens shall be tested to 11.2.3 Seams in the shank shall not exceed a depth of 0.03
PracticeEandbeconsideredsatisfactoryifpassingPracticeE. D or 0.008 in., whichever is greater.
TABLE 3 Mechanical Testing Requirements
Test Conducted Using Full Size
Hardness Test Conducted Using Machined Test Specification
Product
Item Product Length
max min Extension Axial Tensile Yield Strength Tensile Elongation
Strength 0.2 % offset Strength
AB B
1 #3 D . . . . .
B BB
2>3 D-12 in. . . . .
B
3 Over 12 in. . AABBB
A
D denotes nominal diameter of product.
B
Denotes mandatory test. In addition, either all tests denoted by A or all tests denoted by B shall be performed. In case of arbitration full size tests, denoted A, shall be
decisive.
F837−13 (2018)
TABLE 4 Tensile Strength Values for Full-Size Fasteners, lbs
12.2 Whenspecifiedinthepurchaseorder,themanufacturer
Alloy Groups 1 and 2 Alloy shall furnish a test report of the last complete set of chemical
Nominal
Group 5
Stress Area
analysis and mechanical tests for each stock size in each
Size
AF max CW min CW1 min HT min
shipment.
0.060-80 0.00180 153 144 183 288
12.3 When tests of individual shipments are required,
0.073-64 0.00263 223 210 267 420
0.073-72 0.00278 236 222 283 444
Supplementary Requirement S1 must be specified in the
0.086-56 0.00370 314 296 377 592
inquiry and order.
0.086-64 0.00394 334 315 401 630
12.3.1 When the purchaser does not specify the sampling
0.099-48 0.00487 414 390 497 779
0.099-56 0.00523 445 418 533 837
plan a
...
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.
´1
Designation: F837 − 13 F837 − 13 (Reapproved 2018)
Standard Specification for
Stainless Steel Socket Head Cap Screws
This standard is issued under the fixed designation F837; 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.
ε NOTE—S9 Mechanical Property Requirements was editorially corrected in March 2014.
1. Scope*
1.1 This specification covers the chemical and mechanical requirements for stainless steel inch socket head cap screw (SHCS)
with nominal thread 0.060 through 1.500 in. and intended for use in applications requiring general corrosion resistance.
1.2 Three groups of stainless steel alloys are covered, austenitic Group 1 and 2 and martensitic Group 5.
1.3 Four property conditions are covered: austenitic Alloy Groups 1 and 2 in an annealed condition (AF) at 85 ksi maximum,
in two cold worked conditions (CW) at 80 ksi minimum, (CW1) at 102 ksi minimum, and martensitic Alloy Group 5 in a heat
treated condition (HT) at 160 ksi minimum.
1.4 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this
standard.
1.5 The following precautionary caveat pertains only to the test method portion, Section 13, 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.
1.6 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:
A262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
A342/A342M Test Methods for Permeability of Weakly Magnetic Materials
A380 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 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
F606 Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, and
Rivets (Metric) F0606_F0606M
F788/F788M 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
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 Nov. 1, 2013Sept. 1, 2018. Published December 2013September 2018. Originally approved in 1988. Last previous edition approved in 20082013
ɛ1
as F837 – 08.F837 – 13 . DOI: 10.1520/F0837-13E01.10.1520/F0837-13R18.
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 standard’s Document Summary page on the ASTM website.
*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
F837 − 13 (2018)
2.2 ASME Standard:
ASME B18.3 Socket Cap, Shoulder, and Set Screws—Inch Series
2.3 JIS Standard:
JIS G 4311 Heat Resisting Steel Bar and Wire Rods
3. Classification
3.1 The austenitic stainless steel socket head cap screw shall be designated F837 Group 1 or 2 Condition AF, F837 Group 1 or
2 Condition CW, or F837 Group 1 or 2 Condition CW1.
3.2 The martensitic stainless steel socket head cap screw shall be designated F837 Group 5 Condition HT.
4. Ordering Information
4.1 Orders for socket head cap screws under this specification shall include:
4.1.1 Quantity (number of pieces of each item).
4.1.2 Name of the item (socket head cap screws, SHCS).
4.1.3 Size (nominal diameter, thread pitch, thread class, screw length) or part number.
4.1.4 Alloy Group (see 7.1) and Condition (Group 1 or 2 AF, Group 1 or 2 CW, Group 1 or 2 CW1, or Group 5 HT).
4.1.5 ASTM specification and year of issue. When year of issue is not specified, fasteners shall be furnished to the latest issue.
4.1.6 Supplementary requirements, if any, (see S1 through S7).
4.1.7 Additional special requirements, if any, to be specified on the purchase order:
4.1.7.1 Forming (see 5.1).
4.1.7.2 Threading (see 5.2).
4.1.7.3 Surface finish (see 11.1).
4.1.7.4 Alloy selection (see 7.2).
4.1.7.5 Test report (see 12.2).
4.1.7.6 Additional testing (see 12.3).
4.1.7.7 Inspection (see 14.1).
4.1.7.8 Rejection (see 15.1).
4.1.7.9 Certification (see 16.1).
4.1.7.10 Special packaging requirements (see 18.3).
4.1.7.11 Supplementary requirements as needed.
5. Materials and Manufacture
5.1 Heads—Unless otherwise specified the head and socket recess of the screw may be hot forged, cold forged, or machined
at the option of the manufacturer. Users requiring cold forged heads should specify Supplementary Requirements S6.
5.2 Threads—Unless otherwise specified, screws in sizes up to 1.00 in. inclusive and product lengths up to 6 in. inclusive, shall
have threads formed by rolling, except by special agreement with the purchaser. Larger products may be rolled, cut, or ground at
the option of the manufacturer.
6. Heat Treatment
6.1 Austenitic alloys Group 1 or 2 Condition AF screws, following manufacture, shall be annealed by heating to 1900 6
50°F50 °F to obtain maximum corrosion resistance and minimum permeability. The screws shall be held for a sufficient time at
temperature and then cooled at a rate sufficient to prevent precipitation of the carbide and to provide the properties specified in
Table 1.
6.2 When Condition CW or CW1 is specified, the austenitic alloys shall be annealed as specified in 6.1 generally by the raw
material manufacturer, then cold worked to develop specific properties.
6.3 Martensitic alloy Group 5 Condition HT screws shall be hardened and tempered by heating to 1800 6 50°F50 °F sufficient
for austenitization, holding for at least ⁄2 h, rapid air or oil quenching, reheating to 525°F525 °F minimum and holding for at least
1 h and then air cooling to provide the properties specified in Table 1.
7. Chemical Properties
7.1 It is the intent of this specification that screws shall be ordered by alloy group and condition. The chemical composition of
the screw material shall conform to the requirements of Table 2.
Available from Global Engineering Documents, 15 Inverness Way, East Englewood, CO 80112-5704, http://www.global.ihs.com.American Society of Mechanical
Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http://www.asme.org.
Available from Japanese Standards Association (JSA), Mita MT Bldg., 3-13-12 Mita, Minato-ku, Tokyo 108-0073, Japan, http://www.jsa.or.jp.
F837 − 13 (2018)
TABLE 1 Mechanical Property Requirements
B
Full-Size Product Machine Specimen Core Hardness
Alloy
Nominal
Alloy Mechanical
Minimum
Condition Thread
Tensile Minimum Tensile Yield Strength,
Group Property
A Elongation, Vickers Rockwell
C
Diameter
Strength, ksi Extension Strength, ksi ksi
Marking
%
1 AF F837A 0.060–1.500 85 max 0.6D 85 max 55 max 40 210 max 95 HRB max
1 CW F837B 0.060–0.750 80 min 0.4D 80 min 40 min 25 150 min 50 HRA min
1 CW1 F837C 0.060–0.750 102 min 0.4D 87 min 65 min 20 220 min 59 HRA min
2 AF F837D 0.060–1.500 85 max 0.6D 85 max 55 max 40 210 max 95 HRB max
2 CW F837E 0.060–0.750 80 min 0.4D 80 min 40 min 25 150 min 50 HRA min
2 CW1 F837F 0.060–0.750 102 min 0.4D 87 min 65 min 20 220 min 59 HRA min
5 HT F837G 0.060–0.190 180 min . . . . . . . . . . . . 350–423 36–43 HRC
5 HT F837H 0.250–1.500 180 min 0.2D 160 min 120 min 12 350–423 36–43 HRC
A
For CW and CW1 condition fasteners with nominal thread diameter larger than 0.750 in., the mechanical properties and marking shall be agreed upon between the user
and manufacturer.
B
Core hardness is only required when full-size product tensile testing cannot be accomplished.
C
D denotes nominal thread size.
TABLE 2 Chemical Requirements
Composition, % maximum except as shown
Alloy UNS
Alloy
Phosphorus
Group Designation
Carbon Manganese Sulfur Silicon Chromium Nickel Copper Molybdenum
Austenitic Alloys
A B
1 S30300 303 0.15 2.00 0.20 0.15 min 1.00 17.0 to 19.0 8.0 to 10.0 . . . 0.60 max
1 S30400 304 0.08 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 10.5 1.00 . . .
1 S30403 304L 0.030 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 12.0 1.00 . . .
1 S30500 305 0.12 2.00 0.045 0.030 1.00 17.0 to 19.0 10.5 to 13.0 1.00 . . .
1 S38400 384 0.08 2.00 0.045 0.030 1.00 15.0 to 17.0 17.0 to 19.0 . . . . . .
A B
1 S20300 XM1 0.08 5.0 to 6.5 0.040 0.18 to 0.35 1.00 16.0 to 18.0 5.0 to 6.5 1.75 to 2.25 0.50 max
1 S30430 18-9LW 0.10 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.00 to 4.00 . . .
1 S30433 302HQ 0.03 2.00 0.045 0.030 4.00 17.0 to 19.0 8.0 to 10.0 3.0 to 4.0 . . .
C
1 . 304J3 0.08 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.5 1.00 to 3.00 .
2 S31600 316 0.08 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.0 to 3.0
2 S31603 316L 0.03 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.0 to 3.0
Martensitic Alloys
5 UNS41000 410 0.15 1.00 0.040 0.030 1.00 11.5 to 13.5 . . .
A
Free machining grades are not recommended for forged product. These grades may be furnished only when approved by the purchaser.
B
At manufacturer’s option, determined only when intentionally added.
C
304J3 from JIS standard G 4311.
7.2 Unless otherwise specified in the inquiry and purchase order (see Supplementary Requirements S2) the choice of an alloy
from within a group shall be at the discretion of the fastener manufacturer as required by their method of fastener fabrication and
material availability. The specific alloy used by the manufacturer shall be clearly identified on all certification required in the
purchase order and shall have chemical composition conforming to the limits specified in Table 2.
7.3 When chemical analysis is performed by the purchaser using finished fasteners representing each lot, the chemical contents
obtained shall conform to the limits specified in Table 2 for the specific alloy. Chemical contents shall conform to the tolerances
specified in Specification A555/A555M.
7.3.1 In the event of discrepancy, a referee analysis as specified in 13.1 of samples for each lot shall be made in accordance with
12.3.1.
8. Mechanical Properties
8.1 Screws shall be tested in accordance with the mechanical testing requirements for the alloy group and condition nominal
thread diameter, length, and specified minimum tensile strength as specified in Table 3 and shall meet the mechanical requirements
specified for that product in Table 1.
8.2 For products on which both hardness and tension tests are performed, acceptance based on tensile requirements shall take
precedence over low hardness readings (see Table 4).
9. Corrosion Resistance
9.1 Carbide Precipitation:
9.1.1 Rod, bar, and wire in the austenitic alloy groups 1 and 2 (not including the free-machining grade 303) 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 Practice A262.
F837 − 13 (2018)
TABLE 3 Mechanical Testing Requirements
Test Conducted Using Full Size
Hardness Test Conducted Using Machined Test Specification
Product
Item Product Length
max min Extension Axial Tensile Yield Strength Tensile Elongation
Strength 0.2 % offset Strength
A B B
1 #3 D . . . . . . . . . . . . . . .
B B B
2 >3 D-12 in. . . . . . . . . . . . .
B
3 Over 12 in. . . . A A B B B
A
D denotes nominal diameter of product.
B
Denotes mandatory test. In addition, either all tests denoted by A or all tests denoted by B shall be performed. In case of arbitration full size tests, denoted A, shall be
decisive.
TABLE 4 Tensile Strength Values for Full-Size Fasteners, lbs
Alloy Groups 1 and 2 Alloy
Nominal
Group 5
Stress Area
Size
AF max CW min CW1 min HT min
0.060-80 0.00180 153 144 183 288
0.073-64 0.00263 223 210 267 420
0.073-72 0.00278 236 222 283 444
0.086-56 0.00370 314 296 377 592
0.086-64 0.00394 334 315 401 630
0.099-48 0.00487 414 390 497 779
0.099-56 0.00523 445 418 533 837
0.112-40 0.00604 513 483 615 966
0.112-48 0.00661 562 529 674 1 060
0.125-40 0.00796 676 636 811 1 270
0.125-44 0.00830 706 665 848 1 330
0.138-32 0.00909 772 727 927 1 450
0.138-40 0.01015 862 811 1 035 1 620
0.164-32 0.0140 1 191 1 121 1 429 2 240
0.164-36 0.01474 1 252 1 178 1 502 2 360
0.190-24 0.0175 1 490 1 403 1 788 2 800
0.190-32 0.0200 1 699 1 600 2 039 3 200
0.250-20 0.0318 2 705 2 546 3 246 5 090
0.250-28 0.0364 3 092 2 910 3 710 5 820
0.312-18 0.0524 4 457 4 194 5 348 8 380
0.312-24 0.0580 4 936 4 645 5 923 9 280
0.375-16 0.0775 6 587 6 199 7 904 12 400
0.375-24 0.0878 7 465 7 026 8 958 14 000
0.437-14 0.1063 9 036 8 505 10 843 17 000
0.437-20 0.1187 10 091 9 497 12 109 19 000
0.500-13 0.1419 12 061 11 352 14 474 22 700
0.500-20 0.1599 13 596 12 796 16 315 25 600
0.625-11 0.226 19 210 18 080 23 052 36 200
0.625-18 0.256 21 756 20 477 26 108 41 000
0.750-10 0.334 28 429 26 757 34 115 53 400
0.750-16 0.373 31 702 29 837 38 042 59 700
0.875-9 0.462 39 247 . . . . . . 73 900
0.875-14 0.509 43 305 . . . . . . 81 400
1.000-8 0.606 51 488 . . . . . . 97 000
1.000-12 0.663 56 359 . . . . . . 106 000
1.125-7 0.763 64 878 . . . . . . 122 000
1.125-12 0.856
...
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