Why should the edge of the inner hole of the die (middle die or concave die) be slightly rounded? What's the effect?
In fact, not only the mold, but also other molds or parts must be polished. Some are to reduce the resistance of material flow. Some are aimed at the design requirements of parts. Some are to reduce the appearance damage of stamping parts. There is also to prevent personal injury caused by acute angles. In addition, rounded corners are more difficult to wear than right angles.