Patent ID: 7343990

Claim:
An earth boring bit, comprising: a body having three bit legs; a cone rotatably mounted to each of the bit legs, each of the cones having a plurality of rows of teeth formed thereon, each tooth being separated from an adjacent tooth by a valley, each of the rows being separated from an adjacent row by an annular conical band; a layer of hardfacing on each of the teeth, in the valleys between the teeth, and at least partially on the bands between the rows, the hardfacing comprising tungsten carbide particles in a matrix selected from a group consisting of iron, cobalt, nickel and alloys thereof; wherein the conical band on at least one of the cones comprises: an outer edge portion containing a continuous annular strip of the hardfacing; an inner edge portion containing a continuous annular strip of the hardfacing; and a continuous annular central portion between the inner and outer edge portions that is smooth and free of the hardfacing.