0-15 BOLT & NUT TIGHTENING TORQUE Standard bolt & nut tightening torque Tightening torques of standard bolts and nuts are not indicated throughout the manual. Use the charts and table below to judge the standard tightening torque. 1. Judge the tightening torque for the hexagon head bolt, welded bolt or stud bolt having the standard bearing surface according to the tightening torque table by identifying the bolt strength class from the table below. 2. Judge the tightening torque for the hexagon flange bolt based on the threading diameter. 3. The nut tightening torque can be judged from its corresponding bolt type.
BOLT STRENGTH CLASS IDENTIFICATION METHOD AND TIGHTENING TORQUE Identification by actual part Type Shape and class Class Hexagon head bolt (standard) Number in relief or hallmark on the head 4 = 4T 5 = 5T 6 = 6T 7 = 7T 8 = 8T No mark 4T Bolt with two raised lines on head 5T Bolt with three raised lines on head 7T Bolt with four raised lines on head 8T Welded bolt 4T Stud bolt No mark 4T 2 mm groove(s) on one/both edge(s) 6T