100 degree Surgical stainless steel, heat treated and polished to micro finish, spring back dimple dies are dies that have a special angle machined on the faces of both dies. The male dimple die has a concave angle, and the female depth die has a convex angle. This angle causes the material being formed to bend slightly deeper during forming as the dies are pressed together and bottom out. After dimpling the surfaces “springs back” to a flat surface to give a better and smoother aerodynamic finish. Dies have a 1/2″ body diameter and .187″ shank.