NCF fan
EN
6.5Technical enclosures
6.5.1Tightening torques for nuts and bolts
The tightening torques M, for bolts with ISO metric thread, given in the table are applicable in the following con-
ditions:
• Hexagonal head UNI 5737 type screws, cylindrical head UNI 5931 and UNI 6107 type screws, in normal condi-
tions in which they are supplied.
• Tightening torques must be applied slowly using a torque wrench.
While maintaining the same pre-load values, tightening torques must be modified as described below in the fol-
lowing cases:
• Increased by 5% for wide-head UNI 5712 screws.
• Reduced by 10% for zinc-plated oiled screws.
• Reduced by 20% for phosphor-coated oiled screws.
• Reduced by 10% if the screw is tightened with an impulse tightener.
d x pitch [mm] S r [mm] 8.8 M [Nm] 10.9 M [Nm] 12.9 M [Nm]
6 x 1 20,1 1. 10,4 2. 15,3 3. 17,9
7 x 1 28,9 17,2 25 30
8 x 1,25 36,6 25 37 44
10 x 1,5 58 50 73 86
12 x 1,75 84,3 84,3 127 148
14 x 2 115 115 115 115
16 x 2 157 214 314 368
18 x 2,5 192 306 435 509
20 x 2,5 245 432 615 719
22 x 2,5 303 592 843 987
24 x 3 353 744 1060 1240
27 x 3 459 1100 1570 1840
30 x 3,5 561 1500 2130 2500
30