ASTM A574 / A574M

ASTM A574 / A574M - Standard Specification for Alloy Steel Socket Head Cap Screws

This specification covers complete requirement for quenced and tempered high strength alloy steel hexagon socket head cap screws, 0.060 inch through 4 inch in diameter. ASTM A574M is a complete metric companion to specification ASTM A574. Bolting Specialist can manufacture both metric and inch sized hexagon socket head cap screws for high strength application with reference to ASTM A574 specification. We supply all boltings with EN 10204 Type 3.1 certification. ASTM A574/A574M covers chemical, mechanical, tensile, wedge test requirement, etc. As a part of supplementary requirement, this specification allows users to select chemical requirement specific to grades like AISI 4037, 4042, 4137, 4140, 4142, 4145, 4340, 8740, 5137M & 51B37M.

ASTM A574 Supplementary Grades

Grade
AISI 4037 AISI 4042 AISI 4137 AISI 4140 AISI 4142
AISI 4145 AISI 4340 AISI 8740

ASTM A453 Chemical Composition

Element Heat Analysis % Product Analysis %
Carbon, min 0.33 0.31
Phosphorus, max 0.035 0.040
Sulfur, max 0.040 0.045

Tensile Requirements for Coarse Thread Socket Head Cap Screws

Screw Dia (D), inch Threads/inch Tensile Load, min, lbf A Stress Area, in2B Proof Load, min, lbfC
0.073 64 473 0.00263 368
0.086 56 666 0.00370 518
0.099 48 877 0.00487 682
0.112 40 1090 0.00604 846
0.125 40 1430 0.00796 1110
0.138 32 1 640 0.00909 1270
0.164 32 2520 0.0140 1960
0.190 24 3150 0.0175 2450
0.250 20 5730 0.0318 4450
0.3125 18 9440 0.0524 7340
0.375 16 13900 0.0775 10800
0.4375 14 19100 0.1063 14900
0.500 13 25 500 0.1419 19 900
0.625 11 38400 0.226 30500
0.750 10 56 800 0.334 45 100
0.875 9 78500 0.462 62400
1.000 8 103000 0.606 81800
1.125 7 129000 0.763 103000
1.250 7 165000 0.969 131000
1.375 6 196000 1.155 156000
1.500 6 239000 1.405 190000
1.750 5 323000 1.900 256000
2.000 4-1/2 425000 2.500 338000
2.250 4-1/2 552000 3.250 439000
2.500 4 680000 4.000 540000
2.750 4 838000 4.930 666000
3.000 4 1010000 5.970 806000
3.250 4 1 210 000 7.100 958 000
3.500 4 1420000 8.330 1120000
3.750 4 1640000 9.660 1300000
4.000 4 1880000 11.080 1500000

Tensile Requirements for Fine Thread Socket Head Cap Screws

Screw Dia (D), inch Threads/inch Tensile Load, min, lbf A Stress Area, in2B Proof Load, min, lbfC
0.06 80 324   252
0.073 72 500   389
0.086 64 709   552
0.099 56 941   732
0.112 48 1190   925
0.125 44 1490   1160
0.138 40 1830   1420
0.164 36 2650   2060
0.190 32 3600   2800
0.250 28 6500   5100
0.3125 24 10400   8120
0.375 24 15800   12300
0.4375 20 21400   16600
0.500 20 28800   22400
0.625 18 43500   34600
0.750 16 63400   50400
0.875 14 86500   68700
1.000 12 113000   89500
1.125 12 146000   116000
1.250 12 182000   145000
1.375 12 224000   178000
1.500 12 269000   213000

A Values based on 180 ksi for 0.500 and smaller and 170 ksi for sizes larger than 0.500 inch and stress area in accordance with footnote B.
B Stress aread based on handbook H-28 (U.S. Department of Commerce) as follows:
Az = 0.7854 [D - (0.9743/n)]2
Where
Az = Stress area,
D = Nominal screw size, and
n = Threads/inch.
C Values based on 140 ksi for 0.500 and smaller and 135 ksi for sizes larger than 0.500 inch and stress area in accordance with Footnote B.

Mechanical Requirements as per ASTM A574M

Property Class 12.9A
Full Size Screws:  
Tensile or wedge strength, min, Mpa 1220
Proof Load (stress), min, Mpa 970
Machined Test Specimen:  
Yield strength at 0.2% offset, min, Mpa 1100
Tensile strength, min, Mpa 1220
Elongation in 5D, min, % 10A
Reduction of area, min, % 35
Product Hardness:  
Rockwell 38 - 44 HRC
Vickers 372 - 434 DPH

A Elongation is 2 percentage points higher than property class 12.9

Minimum Ultimate Tensile Loads (As per ASTM A574M)

Thread Size Stress Area, mm2 Tensile Load, min, kN Proof Load, kN
M1.6 x 0.35 1.27 1.55 1.23
M2 x 0.4 2.07 2.53 2.01
M2.5 x 0.45 3.39 4.14 3.2
M3 x 0.5 5.03 6.14 4.88
M4 x 0.7 8.78 10.7 8.52
M5 x 0.8 14.2 17.3 13.8
M6 x 1 20.1 24.5 19.5
M8 x 1.25 36.6 44.6 35.5
M10 x 1.5 58.0 70.8 56.3
M12 x 1.75 84.3 103 81.8
M14 x 2 115 140 112
M16 x 2 157 192 152
M20 x 2.5 245 299 238
M24 x 3 353 431 342
M30 x 3.5 561 684 544
M36 x 4 817 997 792
M42 x 4.5 1120 1370 1090
M48 x 5 1470 1790 1430

Wedge Test Angles

Screw Size,
D, inch.		 Wedge Angle, Deg
Body Lengths 2D
or less or
Threaded to the Head		 Body Lengths
Greater than 2D
0.112 - 0.500, incl. 6 10
0.625 - 0.750, incl. 6 8
0.875 - 1.500, incl. 4 6