Stainless Steel Fasteners Pre-Load and Tightening Torques
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This table shows the maximum permissible tightening torques and the resulting maximum preload for A1, A2 and A4 stainless steel fasteners.
For guidance only
Thread Size | Coeff Friction | Preload (Kn) Property class | Tightening Torque (Nm) Property class | Min Breaking Torque | ||||||
---|---|---|---|---|---|---|---|---|---|---|
A1-50 | A2-70 | A4-80 | A1-50 | A2-70 | A4-80 | A1-50 | A2-70 | A4-80 | ||
M1.6 | 0.1 | 0.4 | 0.55 | 0.55 | 0.1 | 0.1 | 0.2 | 0.15 | 0.2 | 0.24 |
0.2 | 0.3 | 0.35 | 0.35 | 0.1 | 0.2 | 0.35 | ||||
0.3 | 0.2 | 0.3 | 0.3 | 0.2 | 0.25 | 0.45 | ||||
M2.0 | 0.1 | 0.5 | 0.6 | 0.6 | 0.15 | 0.2 | 0.3 | 0.3 | 0.4 | 0.48 |
0.2 | 0.4 | 0.5 | 0.5 | 0.25 | 0.3 | 0.4 | ||||
0.3 | 0.25 | 0.36 | 0.36 | 0.4 | 0.4 | 0.55 | ||||
M2.5 | 0.1 | 0.65 | 0.9 | 0.9 | 0.25 | 0.45 | 0.6 | 0.6 | 0.9 | 0.96 |
0.2 | 0.4 | 0.5 | 0.5 | 0.45 | 0.6 | 0.65 | ||||
0.3 | 0.3 | 0.3 | 0.3 | 0.6 | 0.75 | 0.8 | ||||
M3.0 | 0.1 | 0.9 | 1 | 1 | 0.85 | 1 | 1.3 | 1.1 | 1.6 | 1.8 |
0.2 | 0.6 | 0.65 | 0.65 | 1 | 1.1 | 1.6 | ||||
0.3 | 0.4 | 0.45 | 0.45 | 1.25 | 1.35 | 1.85 | ||||
M4.0 | 0.1 | 1.08 | 2.97 | 2.97 | 0.8 | 1.7 | 2.3 | 2.7 | 3.8 | 4.3 |
0.2 | 1.12 | 2.4 | 2.4 | 1.3 | 2.6 | 3.5 | ||||
0.3 | 0.9 | 1.94 | 1.94 | 1.5 | 3 | 4.1 | ||||
M5.0 | 0.1 | 2.26 | 4.85 | 4.85 | 1.6 | 3.4 | 4.6 | 5.5 | 7.8 | 8.8 |
0.2 | 1.83 | 3.93 | 3.93 | 2.4 | 5.1 | 6.9 | ||||
0.3 | 1.49 | 3.19 | 3.19 | 2.8 | 6.1 | 8 | ||||
M6.0 | 0.1 | 3.2 | 6.85 | 6.85 | 2.8 | 5.9 | 8 | 9.3 | 13 | 15 |
0.2 | 2.59 | 5.54 | 5.54 | 4.1 | 8.8 | 11.8 | ||||
0.3 | 2.09 | 4.49 | 4.49 | 4.8 | 10.4 | 13.9 | ||||
M8.0 | 0.1 | 5.86 | 12.6 | 12.6 | 6.8 | 14.5 | 19.3 | 23 | 32 | 37 |
0.2 | 4.75 | 10.2 | 10.2 | 10.1 | 21.4 | 28.7 | ||||
0.3 | 3.85 | 8.85 | 8.85 | 11.9 | 25.5 | 33.9 | ||||
M10.0 | 0.1 | 9.32 | 20 | 20 | 13.7 | 30 | 39.4 | 46 | 65 | 74 |
0.2 | 7.58 | 16.2 | 16.2 | 20.3 | 44 | 58 | ||||
0.3 | 6.14 | 13.1 | 13.1 | 24 | 51 | 69 | ||||
M12.0 | 0.1 | 13.6 | 29.1 | 29.1 | 23.6 | 50 | 67 | 80 | 110 | 130 |
0.2 | 11.1 | 23.7 | 23.7 | 34.8 | 74 | 100 | ||||
0.3 | 9 | 19.2 | 19.2 | 41 | 88 | 117 | ||||
M14.0 | 0.1 | 18.7 | 40 | 40 | 37.1 | 79 | 106 | 210 | 290 | 330 |
0.2 | 15.2 | 32.6 | 32.6 | 56 | 119 | 159 | ||||
0.3 | 12.3 | 26.4 | 26.4 | 66 | 141 | 188 | ||||
M.16.0 | 0.1 | 25.7 | 55 | 55 | 56 | 121 | 161 | |||
0.2 | 20.9 | 44.9 | 44.9 | 86 | 183 | 245 | ||||
0.3 | 17 | 36.4 | 36.4 | 102 | 218 | 291 | ||||
M18.0 | 0.1 | 32.2 | 69 | 69 | 81 | 174 | 232 | |||
0.2 | 26.2 | 56.2 | 56.2 | 122 | 260 | 346 | ||||
0.3 | 21.1 | 45.5 | 45.5 | 144 | 380 | 411 | ||||
M20.0 | 0.1 | 41.3 | 88.6 | 88.6 | 114 | 224 | 325 | |||
0.2 | 33.8 | 72.4 | 72.4 | 173 | 370 | 494 | ||||
0.3 | 27.4 | 58.7 | 58.7 | 205 | 439 | 586 | ||||
M22.0 | 0.1 | 50 | 107 | 107 | 148 | 318 | 424 | |||
0.2 | 41 | 88 | 88 | 227 | 488 | 650 | ||||
0.3 | 34 | 72 | 72 | 272 | 582 | 776 | ||||
M24.0 | 0.1 | 58 | 142 | 142 | 187 | 400 | 534 | |||
0.2 | 47 | 101 | 101 | 284 | 608 | 810 | ||||
0.3 | 39 | 83 | 83 | 338 | 724 | 966 | ||||
M27.0 | 0.1 | 75 | 275 | |||||||
0.2 | 61 | 421 | ||||||||
0.3 | 50 | 503 | ||||||||
M33.0 | 0.1 | 91 | 374 | |||||||
0.2 | 75 | 571 | ||||||||
0.3 | 61 | 680 | ||||||||
M36.0 | 0.1 | 114 | 506 | |||||||
0.2 | 94 | 779 | ||||||||
0.3 | 76 | 929 | ||||||||
M39.0 | 0.1 | 135 | 651 | |||||||
0.2 | 110 | 998 | ||||||||
0.3 | 89 | 1189 | ||||||||
0.1 | 162 | 842 | ||||||||
0.2 | 133 | 1300 | ||||||||
0.3 | 108 | 1553 |
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