BOLT AND NUT TIGHTENING TORQUE
Standard bolt and nut tightening torque
Standard bolt and nut tightening torques are not indicated.
Judge the standard tightening torque as shown below.
1. Determine the tightening torques of the standard seat hexagon head bolts, welded bolts and stud bolts
by identifying the strength type in the table below, and checking the torque in the tightening torque
table.
2.
Determine the tightening torque of hexagon flange bolts by identifying the strength type, and checking
the torque in the tightening torque table.
3.
Determine the tightening torque of nuts by applying the method in item
1
above to the connecting bolt.
BOLT STRENGTH TYPE IDENTIFICATION METHOD AND TIGHTENING TORQUE
Identification by bolt shape
Shape and strength type
Bolt head No.
No mark
Two embossed lines
Three embossed lines
Four embossed lines
No mark
Grooved
Strength type