Standard Tightening Torque
Each fastener should be tightened to the torque specified in each section of this manual. If no description or specification is provided, refer to TIGHTENING TORQUE CHART for the applicable torque for each fastener. When a fastener of greater strength than the original one is used, however, use the torque specified for the original fastener.
Note. For the flanged bolt, flanged nut and self-lock nut of 4T and 7T strength, add 10% to the tightening torque given in the following chart. The following chart is applicable only where the fastened parts are made of steel light alloy.
Tightening torque chart
TIGHTENING TORQUE CHART Strength Unit Thread Diameter (Nominal Diameter) (mm) 4 5 6 8 10 12 14 16 18 A equivalent of 4T strength fastener N.m 1.5 3.0 5.5 13 29 45 65 105 160 kgf-m 0.15 0.30 0.55 1.3 2.9 4.5 6.5 10.5 16 lb-ft 1.0 2.5 4.0 9.5 21.0 32.5 47.0 76.0 116.0 A equivalent of 6.8 strength fastener without flange N.m 2.4 4.7 8.4 20 42 80 125 193 280 kgf-m 0.24 0.47 0.84 2.0 4.2 8.0 12.5 19.3 28 lb-ft 2.0 3.5 6.0 14.5 30.5 58.0 90.5 139.5 202.5 A equivalent of 6.8 strength fastener with flange *:Self-lock nut (6 strength) N.m 2.4 4.9 8.8 21 44 84 133 203 298 kgf-m 0.24 0.49 0.88 2.1 4.4 8.4 13.3 20.3 29.8 lb-ft 2.0 3.5 6.5 15.5 32.0 61.0 96.5 147.0 215.5 A equivalent of 7T strength fastener N.m 2.3 4.5 10 23 50 85 135 210 240 kgf-m 0.23 0.45 1.0 2.3 5.0 8.5 13.5 21 24 lb-ft 2.0 3.5 7.5 17.0 36.5 61.5 98.0 152.0 174.0 A equivalent of 8.8 strength bolt (8 strength nut) without flange N.m 3.1 6.3 11 27 56 105 168 258 373 kgf-m 0.31 0.63 1.1 2.7 5.6 10.5 16.8 25.8 37.3 lb-ft 2.5 4.5 8.0 19.5 40.5 76.0 121.5 187.0 270.0 A equivalent of 8.8 strength bolt (8 strength nut) with flange N.m 3.2 6.5 12 29 59 113 175 270 395 kgf-m 0.32 0.65 1.2 2.9 5.9 11.3 17.5 27 39.5 lb-ft 2.5 5.0 9.0 21.0 43.0 82.0 126.5 195.5 286.0
