HARD FACING MATERIAL FOR ROCK BITS

摘要

An improved hard facing for teeth and other surfaces of milled tooth rock bits comprises steel in the range of from 18 to 32 percent by weight, and filler in the range of from 68 to 82 percent by weight. The filler is cemented tungsten carbide and cast tungsten carbide free, and includes greater than 95 percent by weight single crystal monotungsten carbide particles. The single crystal monotungten carbide particles have a particle size in the range of from 200 to 500 mesh and, preferably in the range of from 200 to 325.