ASTM F837 / F837M - Standard Specification for Stainless Steel Socket Head Cap Screws
This specification covers chemical and mechanical requirements for stainles steel inch (imperial) series socket head cap screws with nominal thread diameter 0.060 through 1.500 inch., intended for use in applications requiring general corrosion resistance. This specification contains two group of stainless steel alloys i.e, Austenitic Group 1 & Martensitic Group 5. ASTM F837M is a companion to ASTM F837 developed for metric size stainless steel socket head cap screws from M1.6 to M38. Four property conditions are covered: austenitic alloy group 1 in as annealed consition (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. Ferrobend manufactures socket head cap screws as per both specifications duly tested and supplied with EN 10204 Type 3.1 Certification. We offer almost all grades under this specification, 304, 304L, 316, 316L, 303, being most commonly used alloys.
ASTM F837 Chemical Requirements
| Composition, %, maximum except as shown |
| UNS Designation |
Alloy Group |
Alloy |
Carbon |
Manganese |
Phosphorus |
Sulfur |
Silicon |
Chromium |
Nickel |
Copper |
Molybdenum |
| Austenitic Alloys |
| S30300 |
1 |
303A |
0.15 |
2.00 |
0.200 |
0.150 min |
1 |
17.0 - 19.0 |
8.0 - 10.0 |
-- |
0.60 maxB |
| S30400 |
1 |
304 |
0.08 |
2.00 |
0.045 |
0.03 |
1 |
18.0 - 20.0 |
8.0 - 10.5 |
1.00 |
-- |
| A30403 |
1 |
304L |
0.03 |
2.00 |
0.045 |
0.030 |
1 |
18.0 - 20.0 |
8.0 - 12.0 |
1.00 |
-- |
| S30500 |
1 |
305 |
0.12 |
2.00 |
0.045 |
0.03 |
1 |
17.0 - 19.0 |
10.5 - 13.0 |
1.00 |
-- |
| S38400 |
1 |
384 |
0.08 |
2.00 |
0.045 |
0.030 |
1 |
15.0 - 17.0 |
17.0 - 19.0 |
-- |
-- |
| S20300 |
1 |
XM1A |
0.08 |
5.00 - 6.50 |
0.400 |
0.18 - 0.35 |
1 |
16.0 - 18.0 |
5.0 - 6.5 |
1.75 - 2.25 |
0.50maxB |
| S30430 |
1 |
18-9LW |
0.10 |
2.00 |
0.045 |
0.030 |
1 |
17.0 - 19.0 |
8.0 - 10.0 |
3.0 - 4.0 |
-- |
| S30433 |
1 |
302HQ |
0.03 |
2.00 |
0.045 |
0.030 |
1 |
17.0 - 19.0 |
8.0 - 10.0 |
3.0 - 4.0 |
-- |
| S31600 |
1 |
316 |
0.08 |
2.00 |
0.045 |
0.030 |
1 |
16.0 - 18.0 |
10.0 - 14.0 |
-- |
2.0 - 3.0 |
| S31603 |
2 |
316 L |
0.03 |
2.00 |
0.045 |
0.030 |
1 |
16.0 - 18.0 |
10.0 - 14.0 |
-- |
2.0 - 3.0 |
| Martensitic Alloys |
| S41000 |
5 |
410 |
0.15 |
1.00 |
0.040 |
0.030 |
1 |
11.5 - 13.5 |
-- |
-- |
-- |
A Free machining grades are not recommended for forged products. These grades may be furnished only when approved by the purchaser.
B At manufacturer's option, determined only when intentionally added.
ASTM F837 Mechanical Properties
| Alloy Group |
Condition |
Nominal Thread DiameterA |
Full Size Product |
Machined Specimen |
Core HardnessB |
| Tensile Strength, ksi |
Minimum ExtensionC |
Tensile Strength, ksi |
Yield Strength, ksi |
Minimum Elongation, % |
Vickers |
Rockwell |
| 1 |
AF |
0.06 - 1.50 |
85 max |
0.6D |
85 max |
55 max |
40 |
210 max |
95 HRB max |
| 1 |
CW |
0.06 - 1.75 |
80 min |
0.4D |
80 min |
40 min |
25 |
150 min |
50 HRA min |
| 1 |
CW1 |
0.06 - 1.75 |
102 min |
0.4D |
87 min |
65 min |
20 |
220 min |
59 HRA min |
| 5 |
HT |
0.06 - 0.19 |
180 min |
-- |
-- |
-- |
-- |
350 - 423 |
36 - 43 HRC |
| 5 |
HT |
0.06 - 1.50 |
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 inch, the mechanical properties shall be agreed upon between the user and the manufacturer.
B Core hardness is only required when full size product tensile testing cannot be accomplished.
C D denoted nominal thread size.
Mechanical Testing Requirements
| Item |
Product Length |
Hardness |
Test Condusted on Full Size Product |
Test Condusted on Machined Test Specification |
| max |
min |
Extension |
Axial Tensile Strength |
Yield Strength 0.2% offset |
Tensile Strength |
Elongation |
| 1 |
≤3 DA |
B |
B |
-- |
-- |
-- |
-- |
-- |
| 2 |
>3 D-12in. |
B |
-- |
B |
B |
-- |
-- |
-- |
| 3 |
Over 12 in. |
B |
-- |
A |
A |
B |
B |
B |
A D Denotes nominal diameter of product.
B Denotes mandatory test. In addition, either all test denoted by A or all test denoted by B shall be performed. In case of arbitration full size tests, denoted A, shall be decisive.
Tensile Stength Values for Full Size Fasteners, lbs
| Nominal Size |
Stress Area |
Alloy Group 1 |
Alloy Group 5 |
| AF max |
CW min |
CW1 min |
HT min |
| 0.060-80 |
0.0018 |
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 |
1060 |
| 0.125-40 |
0.00796 |
676 |
636 |
811 |
1270 |
| 0.125-48 |
0.0083 |
706 |
665 |
848 |
1330 |
| 0.138-32 |
0.00909 |
772 |
727 |
927 |
1450 |
| 0.138-40 |
0.01015 |
862 |
811 |
1035 |
1620 |
| 0.164-32 |
0.01400 |
1191 |
1121 |
1429 |
2240 |
| 0.164-36 |
0.01474 |
1252 |
1178 |
1502 |
2360 |
| 0.190-24 |
0.0175 |
1490 |
1403 |
1788 |
2800 |
| 0.190-32 |
0.02000 |
1699 |
1600 |
2039 |
3200 |
| 0.250-20 |
0.03180 |
2705 |
2546 |
3246 |
5090 |
| 0.250-28 |
0.03640 |
3092 |
2910 |
3710 |
5820 |
| 0.312-18 |
0.05240 |
4457 |
4194 |
5348 |
8380 |
| 0.312-24 |
0.05800 |
4936 |
2654 |
5923 |
9280 |
| 0.375-16 |
0.07750 |
6 587 |
6 199 |
7 904 |
12 400 |
| 0.375-24 |
0.08780 |
7 465 |
7 026 |
8 958 |
14 000 |
| 0.437-14 |
0.1063 |
9 036 |
8 505 |
10 843 |
17 000 |
| 0.437-20 |
0.11870 |
10 091 |
9 497 |
12 109 |
19 000 |
| 0.500-13 |
0.14190 |
12 061 |
11 352 |
14 474 |
22 700 |
| 0.500-20 |
0.15990 |
13 596 |
12 796 |
16 315 |
25 600 |
| 0.625-11 |
0.22600 |
19 210 |
18 080 |
23 052 |
36 200 |
| 0.625-18 |
0.25600 |
21 756 |
20 477 |
26 108 |
41 000 |
| 0.750-10 |
0.33400 |
28 429 |
26 757 |
34 115 |
43 400 |
| 0.750-16 |
0.37300 |
31 702 |
29 837 |
38 042 |
59 700 |
| 0.875-9 |
0.46200 |
39 247 |
-- |
-- |
73 900 |
| 0.875-14 |
0.50900 |
43 305 |
-- |
-- |
81 400 |
| 1.000-8 |
0.60600 |
51 488 |
-- |
-- |
97 000 |
| 1.000-12 |
0.66300 |
56 359 |
-- |
-- |
106 000 |
| 1.125-7 |
0.76300 |
64 878 |
-- |
-- |
122 000 |
| 1.125-12 |
0.85600 |
72 736 |
-- |
-- |
137 000 |
| 1.250-7 |
0.96900 |
82 374 |
-- |
-- |
155 000 |
| 1.250-12 |
1.07300 |
91 200 |
-- |
-- |
172 000 |
| 1.375-6 |
1.15500 |
98 165 |
-- |
-- |
185 000 |
| 1.375-12 |
1.31500 |
111 751 |
-- |
-- |
210 000 |
| 1.500-6 |
1.40500 |
119 446 |
-- |
-- |
225 000 |
| 1.500-12 |
1.58100 |
134 387 |
-- |
-- |
253 000 |
Alloy Condition Identification
| Alloy Condition |
Marking |
| Group 1 AF |
AF |
| Group 1 CW |
CW |
| Group 1 CW1 |
CW1 |
| Group 5 HT |
HT |