Press cutting dies always accompany a problem of "burrs" both at present and in the past. Ironically, dies need to maintain their sharpness to minimize the formation of burrs. Recently, as smaller and more high-precision products have been introduced to the markets, the parts for Kensaku Warigata (grinded split molds) need much higher precision than before.
To minimize the amount of burrs and extend the service life of dies, we face many challenges such as the form of a die. However, the most important points are to maintain a proper clearance between the punch and the die as well as to provide easy replacement of existing parts with spare ones.