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INTRODUCTION
0.3.4 - Tightening torques
The method used to calculate tightening torques (Cs) and traction forces (F0) is compliant with the standard VDI 2230-1.
The coefcient of safety applied is 0.70 of the yield strength of the material.
Tightening torques for 4.8 UNI EN ISO 898-1 screws
Table 20
THREAD CATEGORY NOMINAL TIGHTENING TORQUES
µ 0,10 (VI) µ 0.14 (VII) µ 0.17 (II)
CS* NOM (NM) CS* NOM (NM) CS* NOM (NM)
4x0.70 1 0.9 1.1 1.2
2 0.8 1.0 1.1
3 0.7 0.9 1.0
5x0.80 1 1.8 2.2 2.4
2 1.7 2.0 2.3
3 1.5 1.8 2.0
6x1.00 1 3.0 3.6 4.0
2 2.8 3.4 3.8
3 2.5 3.0 3.3
7x1.00 1 4.9 6.0 6.7
2 4.6 5.6 6.3
3 4.0 5.0 5.6
8x1.00 1 7.8 9.7 10.9
2 7.3 9.1 10.2
3 6.5 8.0 9.0
8x1.25 1 7.3 9.0 10.0
2 6.9 8.4 9.4
3 6.1 7.4 8.3
10x1.00 1 15.9 20.0 22.5
2 14.9 18.7 21.1
3 13.2 16.6 18.6
10x1.25 1 15.2 18.9 21.2
2 14.2 17.7 19.8
3 12.6 15.6 17.5
10x1.50 1 14.4 17.8 19.9
2 13.5 16.7 18.6
3 12.0 14.7 16.4
12X1.25 1 27 34 38
2 25 31 35
3 22 28 31
12x1.50 1 26 32 36
2 24 30 34
3 21 27 30
12x1.75 1 25 31 34
2 23 29 32
3 20 25 28
14x1.50 1 42 53 59
2 40 49 56
3 35 44 49
14x2.00 1 39 49 54
2 37 46 51
3 33 40 45
16x1.50 1 65 82 92
2 61 76 86
3 54 67 76
16x2.00 1 61 76 85
2 57 71 80
3 51 63 70
18x1.50 1 94 119 134
2 88 111 125
3 78 98 111
18x2.50 1 85 105 117
2 79 98 109
3 70 87 97