Bit leg outer surface hardfacing on earth-boring bit

摘要

An earth-boring bit has bit legs having hardfacing covering the majority of the outer surface. The hardfacing may have gaps at an area surrounding the ball plug and an area around a fixture dimple. The hardfacing may be multi-layer, with the layers differing in composition. Recesses may be located at the leading and trailing edges of the supporting metal so as to provide a thicker area of hardfacing at these corners. The supporting metal of the outer surface of the bit leg may also have an upper cylindrical section and a lower tapered section. The hardfacing has a constant outer diameter but will taper in thickness in the lower tapered section. The thickness of the hardfacing may also vary in a circumferential direction with a greater thickness over at least one of the corners.