Arc Stud Torque Strength

INCH Torque Figures
METRIC Torque Figures

Formulas Used to Calculate the Data

  • A = Mean Effective Thread Area (META) *
  • D = Nominal Thread Diameter
  • L = Tensile Load in Pounds
  • N = Threads per Inch
  • S = Tensile Stress in PSI
  • T = Torque in Inch Pounds

Calculations

  • Tensile Load: L = SA
  • Torque: T = 0.2 × D × L
  • META: A = π/4 × {D - (0.9743/N)}²

Safety Considerations

In practice, studs should not be used at their yield load. A factor of safety, typically 60%, should be applied but may vary depending on the application.

*META is used instead of root area in calculating screw strengths because of closer correlation with actual tensile strength. META is based on mean diameter, which is the diameter of an imaginary coaxial cylinder passing through the thread profile approximately midway between the minor and pitch diameters.

Mild Steel

Thread Size
#10 0.190 24 0.018 877 964 33† 37† 50,000 55,000
32 0.020 1000 1100 38† 42†
1/4 0.250 20 0.032 1591 1750 7 7
28 0.036 1819 2001 8 8
5/16 0.3125 18 0.052 2622 2884 14 15
24 0.058 2903 3194 15 17
3/8 0.375 16 0.077 3874 4262 24 27
24 0.088 4391 4831 27 30
7/16 0.4375 14 0.106 5315 5847 39 43
20 0.119 5936 6529 43 48
1/2 0.500 13 0.142 7095 7804 59 65
20 0.160 7998 8797 67 73
5/8 0.625 11 0.226 11300 12430 118 129
18 0.256 12798 14078 133 147
3/4 0.750 10 0.334 16723 18395 209 230
16 0.373 18648 20513 233 256
7/8 0.875 9 0.462 23087 25395 337 370
14 0.509 25474 28021 371 409

† in lbs.
* Torque figures are based on the assumption that excessive deformation of the thread has not altered the proportional relationship between torque and tension.

Stainless Steel

Thread Size
#10 0.190 24 0.018 701 1490 27† 57† 40,000 85,000
32 0.020 800 1699 30† 65†
1/4 0.250 20 0.032 1273 2705 5 11
28 0.036 1455 3092 6 12
5/16 0.3125 18 0.052 2097 4457 11 23
24 0.058 2323 4936 12 26
3/8 0.375 16 0.077 3100 6587 19 41
24 0.088 3513 7465 22 47
7/16 0.4375 14 0.106 4252 9036 31 66
20 0.119 4749 10091 35 74
1/2 0.500 13 0.142 5676 12061 47 101
20 0.160 6398 13596 53 113
5/8 0.625 11 0.226 9040 19210 94 200
18 0.256 10238 21756 107 227
3/4 0.750 10 0.334 13378 28429 167 335
16 0.373 14918 31702 186 396
7/8 0.875 9 0.462 18469 39247 269 572
14 0.509 20379 43305 297 632

† in lbs.
* Torque figures are based on the assumption that excessive deformation of the thread has not altered the proportional relationship between torque and tension.

Metric Mild Steel

Thread Size
M5 0.1969 31.75 0.022 1084 1193 43† 47† 50000 55000
M6 0.2362 25.40 0.031 1537 1691 73† 80†
M8 0.3150 20.32 0.056 2800 3080 15 16
M10 0.3937 16.93 0.089 4437 4881 29 32
M12 0.4724 14.51 0.129 6451 7096 51 56
M16 0.6299 12.70 0.240 12018 13220 126 139
M20 0.7874 10.16 0.376 18778 20656 246 271
M22 0.8661 10.16 0.466 23298 25628 336 370
M24 0.9449 8.46 0.541 27035 29738 426 468

† in lbs.
* Torque figures are based on the assumption that excessive deformation of the thread has not altered the proportional relationship between torque and tension.

Metric Stainless Steel

Thread Size
M5 0.1969 31.75 0.022 867 1843 34† 73† 40000 85000
M6 0.2362 25.40 0.031 1230 2614 58† 123†
M8 0.3150 20.32 0.056 2240 4760 12 25
M10 0.3937 16.93 0.089 3550 7544 23 49
M12 0.4724 14.51 0.129 5160 10966 41 86
M16 0.6299 12.70 0.240 9614 20431 101 214
M20 0.7874 10.16 0.376 15022 31923 197 419
M22 0.8661 10.16 0.466 18638 39607 269 572
M24 0.9449 8.46 0.541 21628 45959 341 724

† in lbs.
* Torque figures are based on the assumption that excessive deformation of the thread has not altered the proportional relationship between torque and tension.

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