PURPOSE: To perform a high temperature cutting operation for steel materials in an efficient manner, by using a high pressure sintered body of cubic system boron nitride as a tip for a pointed end of a holder having a forced cooling device.
CONSTITUTION: A tip holder 1 is provided with a water-cooled jacket 2 as a forced cooling device. A tip 3 consisting of a high pressure sintered body of cubic system boron nitride is welded to the tip end of the holder 1 by means of brazing. The water-cooled jacket 2 is supplied with cooling water through a cold water pipe 2a, while the cooling water is discharged out by way of a drain port 2b whereby high temperature heat produced in cutting a high temperature work W is cooled. Accordingly, the work W being heated at a temperature of 700W 1,000°C can be efficiently cut off.
TSUKAMOTO RIYUUICHI
YUGAWA MASAYOSHI
KISHIDA YUKIMARE
