High Strength hex head bolt 10.9 applied on the automotive industry

Bolts made of high strength steel, or requiring greater pre-tightening force, can be called high strength bolts.

High-strength bolts are mostly used for the connection of bridge, rail, high pressure and ultra-high voltage equipment.

The fracture of this kind of bolt is mostly brittle fracture.

Applied to high strength bolts on ultra-high voltage equipment, in order to ensure the sealing of the container, it is necessary to apply a large prestress.

Before plating process

Hot rolled coil strip- (cold dial) -spherical (softening) annealing-mechanical phosphorus removal-pickling-cold dial-cold forging forming-thread processing-heat treatment-inspection