ASTM F837-20

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: F837 − 13 (Reapproved 2018) F837 − 20
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.
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, 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.
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
2.2 ASME Standard:
ASME B18.3 Socket Cap, Shoulder, and Set Screws—Inch Series
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 Sept. 1, 2018May 1, 2020. Published September 2018May 2020. Originally approved in 1988. Last previous edition approved in 20132018 as
ɛ1
F837 – 13 .(2018). DOI: 10.1520/F0837-13R18.10.1520/F0837-20.
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.
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
F837 − 20
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 °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.
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.
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 − 20
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 °F sufficient for
austenitization, holding for at least ⁄2 h, rapid air or oil quenching, reheating to 525 °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.
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.
TABLE 2 Chemical Requirements
Composition, % maximum except as shown shown, ellipses indicate no requirement for listed element
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 . . . 0.60max
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
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 . . .
C
1 S30400 304 0.08 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 10.5 . . .
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 . . .
C
1 S30403 304L 0.030 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 12.0 . . .
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 . . .
C
1 S30500 305 0.12 2.00 0.045 0.030 1.00 17.0 to 19.0 10.0 to 13.0 . . .
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 0.50max
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
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 .
D
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 . . .
5 S41000 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
1.00 % Cu max allowed by this standard for formability at manufacturer’s option.
D
304J3 304J3 from JIS standard G 4311.
F837 − 20
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 72 736 . . . . . . 137 000
1.250-7 0.969 82 374 . . . . . . 155 000
1.250-12 1.073 91 200 . . . . . . 172 000
1.375-6 1.155 98 165 . . . . . . 185 000
1.375-12 1.315 111 751 . . . . . . 210 000
1.500-6 1.405 119 446 . . . . . . 225 000
1.500-12 1.581 134 387 . . . . . . 253 000
9.1.2 As stated in Practices A262, 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.
10. Dimensions
10.1 Unless otherwise specified, the products shall conform to the requirements of ASME B18.3.
11. Workmanship, Finish, a
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