Patent ID: 8323372

Claim:
A rotary cone rock bit for drilling earthen formations comprising: a body having a number of legs that extend therefrom; cutting cones rotatably disposed on an end of each leg; a plurality of cutting inserts disposed in the cutting cones, wherein at least one of the plurality of cutting inserts has an outer, formation engaging wear surface including a cermet material having engineered properties of fractures toughness, thermal shock resistance, and wear resistance, the cermet material consisting of: a first phase of tungsten carbide grains; and a second phase of binder alloy bonding the grains, wherein the binder alloy comprises Co, Ni, Fe, C and Mn; wherein the binder alloy comprises in the range of from about 10 to 30 percent by weight Co based on the total weight of the binder alloy, wherein the cermet material comprises in the range of from about 10 to 30 percent by weight binder alloy, and wherein the binder alloy has a coefficient of thermal expansion less than about 6 ppm/° C. within a temperature range of from 100 to 700° C.