MANUFACTURE OF TWIST CHIP

摘要

PURPOSE:To increase accuracy of twist in a die and to obtain highly accurate twist chips by forming twist chips using a heat resistant steel twist forming die coated with an excellently heat resistant ceramic. CONSTITUTION:The twist forming die 1 is made of a heat resistant steel coated with a ceramic. a flat chip made of sintered hard alloy is set in a straight groove 2 and is pressed down by a punch 4 to a twisted groove 3. A zone where the chip deforms plastically following the twisted groove 3 is heated to a temperature range in which the chip can get sufficient deformability by a high-frequency coil 5. The ceramic has an excellent heat resistance, so that the heat resistant steel die 1 coated with the ceramic reduces deformation of the die at high temperatures and increases a maintainable ability of the accuracy of twist in the die remarkably.