Generally speaking, stamping parts need to have a certain R, and it is impossible to achieve a complete sharp corner, but the visually perceived "sharp corner" itself has a certain R:

1. For deep drawing, a larger R can be used in deep drawing, and a smaller R angle can be achieved by adding shaping in the later process.

2. For flanging (flanging), the minimum angle of R can be directly used: the angle of R is not processed during processing, and the small angle of R is polished with sandpaper during debugging. Why can't you reach the real sharp corner? See the figure below.

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I'm afraid blanking needs a certain r angle. Generally, a blanking die is used, otherwise the cutting edge is easy to collapse and wear too fast. For a small amount of blanking, use plasma cutting machine or numerical control laser cutting machine.