Standard tungsten-cobalt carbide bonds, depending on their hardness and purpose, are produced by cold (No. 3, 20–25 HRC, and No. 4, 30–35 HRC) and hot (No. 5, 50–55 HRC) pressing. Sintering temperatures of bond matrices vary from 1150 (No. 3) to 1350°C (No. 5) and in a reducing medium do not lead to the appearance of noticeable traces of graphitization or loss of mechanical strength in perfect single crystals of natural diamond.