| abstract |
An earth-boring bit has cutting elements inserted within holes in the cutter support. The cutting element has a body of a fracture-tough material, preferably tungsten carbide which contains a binder of a soft metal. A layer of a composite carbide which is substantially free of a binder is attached to the cutting end of the body. One cutting element has a chisel-shaped cutting end with two flanks that converge. One of the flanks has the layer of binderless carbide. This insert is located at a junction between the gage surface and heel surface for engaging the sidewall of the bore. Also, gage inserts located in the gage surface have outer ends containing a layer of binderless carbide. |