PURPOSE: To increase transverse rupture strength, by generating the forging flow in the desired direction with the application of the plastic working such as rolling from the outer periphery to the material prior to working of the tool for cutting and working an edge tip with the execution of machining thereafter.

CONSTITUTION: In the case of using a bar like tool steel 1 as the material, the forging flow 11 is flowed gently in parallel to the center direction thereof. Now, prior to the edge tip working, a plastic working is executed on the outer peripheral part by pressing a rolling on the outer peripheral face of the tool steel 1. On execution of a plastic working 10b, the forging flow 11 is deformed in a wavy shape. Thereafter, an edge tip 20b is formed by the method similar to the ordinary. When the edge tip 20b is thus formed, the forging flow 11 remains in a wavy form on the edge tip 20b and the forging flow 11 becomes at the angle close to 90° not in parallel to the cutting direction. Consequently, the transverse rupture strength is increased and also the life can be prolonged, because of the forging flow being improved so as to become no parallel to the cutting resistance.