. MAINTENANCE STANDARD TIGHTENING TORQUES FOR BOLTS AND NUTS STANDARD TIGHTENING TORQUES FOR BOLTS AND NUTS If parts made from plastic, such as panels, are tightened to an excessive torque, the tightened portion may break. Always keep to the standard tightening torque for nuts and bolts. Apply the following table for Hydraulic Hose. Face seal 4 - 19 TORQUE LIST When tightening torqu es are not e ntered at concerned parts , tighten the metric nuts an d bolts to the torque sh own in the table below.
The tig htening torque i s determined by the width acros s the flats (b) of th e nut and bol If it is n ecessary to replace any nu t or bolt, a lways use a Komatsu genuine part of the sa me size as the part that was replaced. Please order nuts and bolts from your Komatsu distributor.
Thread diamete of bolt (a)(mm Width r across flats ) (b)(mm) Tightening torque Target value Service limit Nm kgm lbft Nm kgm lbft 6 8 10 12 14 10 13 17 19 22 13.2 31 66 113 177 1.35 3.2 6.7 11.5 18 9.8 23.1 48.5 83.2 130.2 11.8-14.7 27-34 59-74 98-123 157-196 1.2-1.5 2.8-3.5 6.0-7.5 10.0-12.5 16.0-20.0 8.7-10.8 20.3-25.3 43.4-54.2 72.3-90.4 115.7-144.7 16 18 20 22 24 24 27 30 32 36 279 382 549 745 927 28.5 39 56 76 94.5 206.1 282.1 405.0 549.7 683.5 245-309 343-425 490-608 662-829 824-1030 25.0-31.5 35.0-43.5 50.0-62.0 67.5-84.5 84.0-105.0 180.8-227.8 253.2-314.6 361.7-448.4 488.2-611.2 607.6-759.5 27 30 33 36 39 41 46 50 55 60 1320 1720 2210 2750 3280 135.0 175.0 225.0 280.0 335.0 976.5 1265.8 1627.4 2025.2 2423.1 1180-1470 1520-1910 1960-2450 2450-3040 2890-3630 120.0-150.0 155.0-195.0 200.0-250.0 250.0-310.0 295.0-370.0 868.0-1085.0 1121.1-1410.4 1446.6-1808.3 1808.3-2242.2 2133.7-2676.2 Nominal - No.
of threads (a) Width across flats (b) (mm) Tightening torque Target value Permissible range Nm kgm lbft Nm kgm lbft 9/16 -18UNF 19 44 4.5 32.5 35 to 63 3.5 to 6.5 25.3 to 39.8 11/16 -16UN 22 74 7.5 54.2 54 to 93 5.5 to 9.5 39.8 to 68.7 13/16 -16UN 27 103 10.5 75.9 84 to 132 8.5 to 13.5 61.5 to 97.6 1 -14UNS 32 157 16.0 115.7 128 to 186 13.0 to 19.0 94.0 to 137.4 13/16 -12UN 36 216 22.0 159.1 177 to 245 18.0 to 25.0 130.2 to 180.8