A study on the improvement of the accuracy of a shaving process using a progressive die

Shaving is widely used as a finish process to generate a smooth sheared surface from a sheared surface originally obtained by blanking or piercing. In the sheet metal forming industry, progressive operations are commonly used to increase productivity. However, it is difficult to utilize shaving in a progressive die because a blank is dropped down after blanking. In this study, a method that addresses this issue is introduced, and the two-stage progressive operation of half-blanking and blank-shaving is suggested. For this study, a square part made by blanking and piercing is considered, and a progressive die that includes piercing, pierce-shaving, half-blanking and blank-shaving is prepared for a specimen of cold rolled steel sheet. Experiments are carried out involving the process parameters of the shaving allowance, shaving clearance and the half-blanking penetration depth. It was found that the proposed method using a progressive die offers a completely smooth sheared surface along with feasible working conditions for a cold rolled steel sheet with a thickness of 1.56 mm.