15 degrees. According to the relevant public information, the process supplement should be set as an obtuse angle of 15 degrees, with the maximum not exceeding 20 degrees. Stamping is a kind of forming processing method to apply external force to plates, strips, pipes and profiles by means of presses and dies, so that they can be plastically deformed or separated, thus obtaining workpieces (stamping parts) with required shapes and sizes. Stamping and forging belong to plastic processing (or pressure processing) and are collectively called forging. Stamping blanks are mainly hot-rolled and cold-rolled steel plates and strips.