1, shear and fracture of cold-drawn round steel

2. Plane chamfering of instrument car

3, stamping, directly on the molding die once, the die needs to calculate the springback. If the material fluctuates greatly, the inspection and shaping processes will be added.

4, heat treatment, just ordinary heat treatment, high frequency is more troublesome, not applicable here. This is the conventional heat treatment of spring steel, 860-degree oil quenching and 420-degree tempering.

5. The surface is black, why should it be polished?

Pull rod, the name of which is spring, can be used as a special-shaped spring.

Where is the factory? No, I'll get someone to do it for you.