ROCK BITS AND INSERTS THEREFOR

摘要

The present invention is a rock bit insert including a polycrystalline diamond surface on an insert body having a head portion made from a material with elasticity and thermal expansion properties advantageously tailored for use in three types of rock bits, as well as the three types of rock bits made with such inserts. The three types of bits are a roller cone rock bit adapted to be used with mud as the drilling fluid, a roller cone rock bit adapted to be used with air as the drilling fluid, and a percussion rock bit.