To provide a punching work method having a shear angle capable of coping with various shapes and a punching tool with excellent concentricity of a punch and a die in very small clearance.
A projecting shear angle forming electrode is made by using a tapered electrode for a die material plate. The premade punch is sent in concentrically with the made shear angle forming electrode while performing electric discharge machining. The shear angle is formed on a punch bottom surface. The punch with the shear angle is formed as an electric discharge machining electrode. The die is made by performing the electric discharge machining on the die material plate to make the die with excellent concentricity with the punch having the shear angle in the very small clearance.
MASAKI TAKESHI
