Standard Bolt & Nut Tightening Torque; Bolt Strength Class Identification Method - Toyota 8FBCU 20 Repair Manual

STANDARD BOLT & NUT TIGHTENING TORQUE
Standard bolt and nut tightening torques are not indicated.
Judge the standard tightening torque as shown below.
1. For tightening torque of hexagon head bolt, welded bolt and stud bolt with the standard bearing surface, identify
bolt class based on the below chart and then determine using the tightening torque table.
2. For tightening torque of hexagon flange bolts, identify bolt class based on the below chart and then determine
using the tightening torque table.
3. For tightening torque of nuts, check the mating bolt and use the method 1.

BOLT STRENGTH CLASS IDENTIFICATION METHOD

Identification by Bolt Shape
Hexagon head bolt
Welded bolt
Stud bolt
Shape and class
Bolt head No.
No mark
Two protruding lines
Three protruding lines
Four protruding lines
No mark
Grooved
0-15
Class
4 = 4T
5 = 5T
6 = 6T
7 = 7T
8 = 8T
4T
5T
7T
8T
4T
4T
6T