Use constructional type of progressive dies , change present one step operation of single die construction for two-step blanking , i.
Use constructional type of progressive dies, change present one step operation of single die construction for two-step blanking, i. e, first step semi-blanking, second ejecting material.
And meanwhile, two kinds of twisting formation devices are introduced, which could serve as a reference for the design and manufacture of similar multi-position progressive dies.
