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ASTM F837/F837M Stainless Steel Screws Specification

Stainless Steel Socket Head Cap Screws for use in applications requiring general corrosion resistance

ASTM F837/F837M Socket Head Cap Screws, Allen Bolts

ASTM F837 / F837M specification covers the chemical and mechanical requirements for stainless steel inch socket head cap screw (SHCS) with nominal thread #0 through 1 1/2 inch imperial sizes and M1 to M36 and intended for use in applications requiring general corrosion resistance. Three groups of stainless steel alloys are covered, austenitic Group 1 and 2 and martensitic Group 5. 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. he 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. The martensitic stainless steel socket head cap screw shall be designated F837 Group 5 Condition HT. 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. Unless otherwise specified, screws in sizes up to 1.00 inch inclusive and product lengths up to 6 inch 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.

ASTM F837/F837M Chemical Requirements

Alloy Group UNS Designation Alloy C Mn P S Si Cr Ni Cu Mo
1 S30300 303A 0.15 2.00 0.20 0.15 min 1.00 17.0 to 19.0 8.0 to 10.0 . . . 0.60 maxB
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 . . . . . .
S20300 XM1A 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 maxB
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 . . .
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 . . .
... 304J3C 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
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
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) 304J3 from JIS standard G 4311.

ASTM F837/F837M Mechanical Property Requirements

Alloy Group Condition Alloy 
Mechanical
Property 
Marking		 Nominal Thread DiameterA Full-Size Product Machine Specimen Core HardnessB
Tensile Strength, ksi Minimum ExtensionC Tensile Strength, ksi Yield Strength, ksi Minimum Elongation,
%		 Vickers Rockwell
1 AF F837A 0.060-1.500 85 max 0.6D 85 max 55 max 40 210 max 95 HRB max
CW F837B 0.060-0.750 80 min 0.4D 80 min 40 min 25 150 min 50 HRA min
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
CW F837E 0.060-0.750 80 min 0.4D 80 min 40 min 25 150 min 50 HRA min
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
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.

ASTM F837/F837M Mechanical Testing Requirements

Item Product Length Hardness Test Conducted Using Full Size Product Test Conducted Using Machined Test Specification
max min Extension Axial Tensile Strength Yield Strength 0.2 % offset Tensile Strength Elongation
1 ≤3 D A B B . . . . . . . . . . . . . . .
2 >3 D-12 in. 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 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.

ASTM F837/F837M Tensile Strength Values for Full-Size Fasteners (Inch)

Nominal Size Stress Area Alloy Groups 1 and 2 Alloy Group 5
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

ASTM F837/F837M Tensile Strength Values for Full-Size Fasteners (Metric)

Nominal Size and Thread Pitch Stress Area, mm 2 A Property Classes
A1-50 A1-55 A1-70 C1-110
Tensile Strength, kNB Tensile Strength, kNC Tensile Strength, kND Tensile Strength, kNE
M1.6 × 0.35 1.27 0.74 0.70 0.89 1.40
M2 × 0.4 2.07 1.21 1.14 1.45 2.28
M2.5 × 0.45 3.39 1.98 1.87 2.37 3.73
M3 × 0.5 5.03 2.94 2.77 3.52 5.53
M3.5 × 0.6 6.78 3.97 3.73 4.75 7.46
M4 × 0.7 8.78 5.14 4.83 6.15 9.66
M5 × 0.8 14.2 8.30 7.80 9.93 15.6
M6 × 1 20.1 11.8 11.1 14.1 22.1
M8 × 1.25 36.6 21.4 20.1 25.6 40.3
M10 × 1.5 58.0 33.9 31.9 40.6 63.8
M12 × 1.75 84.3 49.3 46.3 59.0 92.7
M14 × 2 115 67.5 63.5 80.8 126.5
M16 × 2 157  91.7 86.2 110 173 
M20 × 2.5 245  143  135 171  270 
M24 × 3 353  206  . . . . . . 388 
M30 × 3.5 561  328  . . . . . . 617 
M36 × 4 817  478  . . . . . . 899 

ASTM F837/F837M Mechanical Property Requirements bottom

Alloy Group Condition Nominal Diameter Full Sized Product Mechanical Specimen Hardness
Tensile Strength, ksi Extension, min Tensile Strength, ksi Yeild Strength, ksi Elongation, % Vickers, min. max Rockwell, min. max
All  CW 0.060-0.625 95 min 0.4D 90 min 30 min 10 159 330 B80 C33
0.750-1.500 70 min 0.2D 70 min 26 min 20 157 310 B74 C3

ASTM F837/F837M Bolting Surface Treatment Specifications

ASTM F837/F837M Bolting Components Marking

Product Shall be Marked with our manufacturing trade mark "TorqBolt" or "TB" along with the designated Grade.
Grade and manufacturer’s identification symbols shall be applied to one end of studs and to the heads of bolts and screws of all sizes. (If the available area is inadequate, the grade symbol may be marked on one end and the manufacturer’s identification symbol marked on the other end.) For bolts and screws smaller than 1⁄4 in. [6 mm] in diameter and studs smaller than 3⁄8 in. [10 mm] in diameter and for 1⁄4 in. [6 mm] in diameter studs requiring more than a total of three symbols, the marking shall be a matter of agreement between the purchaser and the manufacturer.

ASME Dimensional Standards

B18.3 Socket Cap, Shoulder, and Set Screws-Inch Series

ASTM F837/F837M Bolting Certifications

  • EN 10204 3.1
  • EN 10204 3.2
  • PED 2014/68/EC
  • MERKBLATT AD 2000 W2/W7/W10
  • API 20 E BSL 1/ BSL 2
  • NACE MR 0175
  • NACE MR 0103

ASTM F837/F837M Testing Standards

ASME Threading Specifications

ASME B1.1 Unified Inch Screw Threads (UN and UNR Thread Form)
ASME B1.3 Screw Thread Gaging System for Dimensional Acceptability - Inch Screw Threads (IN, UNR, and UNJ)
ASME B1.13M Metric Screw Threads - M Profile
ASME B1.21M Metric Screw Threads - MJ Profile
ASME B1.2 Gauges & gauging for Unified Screw Threads(Imperial)

ASTM F837/F837M Supplementary Requirements

S1 Shipment Lot Testing
S2 Alloy Control
S3 Permeability
S4 Material Identification
S5 Manufacturer Identification
S6 Forged Heads
S7 Corrosion Resistance Tests
S8 Passivation
S9 Mechanical Property Requirements