MAINTENANCE BASICS TORQUE FOR STANDARD NUTS AND BOLTS Provided that no other values are given, tighten the metric screws with a strength value of 10.9 and the nuts with a strength value of 10 applying the torques given in the tables. The torque that must be applied depends on the diameter of the thread (a) and the size of the spanner (b) of both the nut and the screw. Always replace nuts and screws by original parts. Dimensions and quality of replaced parts and original parts must be identi- cal. Do not apply excessive torque to plastic parts. Tighten plastic parts only manually.
7-20 METRIC BOLTS COARSE-PITCH-THREAD - TENSILE STRENGTH CLASS 10.9 Thread diameter of bolt mm Width across flat mm Steel Aluminium Cast (a) (b) Nm kpm Nm kpm M6 10 14 1.4 7.7 0.77 M8 13 35 3.5 19.0 1.9 M10 17 (15) 70 7.0 37.0 3.7 M12 19 115 11.5 64.0 6.4 M14 22 185 18.5 101.5 10.15 M16 24 280 28.0 158.0 15.8 M18 27 390 39.0 218.0 21.8 M20 30 560 56.0 306.5 30.65 M22 32 750 75.0 416.0 41.6 M24 36 960 96.0 528.5 52.85 M27 41 1400 140.0 774.0 77.4 M30 46 1900 190.0 1053.0 105.3 M33 50 2600 260.0 - - M36 55 3300 330.0 - - M39 60 4300 430.0 - -