21. STANDARD TIGHTENING TORQUES FOR BOLTS AND NUTS 21.2 TORQUE LIST Unless otherwise specified, tighten the metric bolts and nuts to the torque shown in the table. The tightening torque is determined by the width across the flats of the nut and bolt. If it is necessary to replace any nut or bolt, always use a Komatsu genuine part of the same size as the part that was replaced. Nm (newton meter): 1 Nm 0.1 kgm 0.74 lbft . = = .. .. NOTICE When tightening panels or other parts having tightening fixtures made of plastic, be careful not to use excessive tightening torque: doing so will damage the plastic parts.
PC450-ENG 3-17 Thread diameter of bolt (mm) (a) Width across flat (mm) (b) Nm kgm lbft 10 13 16/17 18/19 21/22 13.2 ± 1.4 31.4 ± 2.9 65.7 ± 6.8 112 ± 9.8 177 ± 19 1.35 ± 0.15 3.2 ± 0.3 6.7 ± 0.7 11.5 ± 1.0 18.0 ± 2.0 16 18 20 22 24 24 27 30 32/34 36 279 ± 29 383 ± 39 549 ± 58 745 ± 78 927 ± 98 28.5 ± 3 39 ± 3 56 ± 6 76 ± 8 94.5 ± 10 206 ± 21 282 ± 29 405 ± 43 549 ± 58 684 ± 72 27 30 33 36 39 41 46 50 55 60 1320 ± 140 1720 ± 190 2210 ± 240 2750 ± 290 3280 ± 340 135 ± 15 175 ± 20 225 ± 25 280 ± 30 335 ± 35 973 ± 100 1270 ± 140 1630 ± 180 2030 ± 210 2420 ± 250