Patent ID: 7475743

Claim:
A drill bit, comprising: a bit body formed from a matrix powder, wherein the matrix powder comprised: (a) stoichiometric tungsten carbide particles having a mesh size between 325 mesh and 625 mesh and present in an amount less than or equal to 30 weight percent of the matrix powder; (b) cemented tungsten carbide particles having a mesh size between 170 mesh and 625 mesh and present in an amount less than or equal to 40 weight percent of the matrix powder; and (c) cast tungsten carbide particles having a mesh size between 60 mesh and 325 mesh and present in an amount less than or equal to 60 weight percent of the matrix powder; at least one cutting element for engaging a formation, wherein after formation with the matrix powder, the bit body has: an erosion rate of less than 0.001 in/hr; a toughness of greater than 20 ksi(in 0.5 ); and a transverse rupture strength of greater than 140 ksi.