Abstract: A rotary drill bit includes a bit body substantially formed of a particle-matrix composite material having an exterior surface and an abrasive wear-resistant material disposed on at least a portion of the exterior surface of the bit body. Methods for applying an abrasive wear-resistant material to a surface of a drill bit are also provided.

Abstract: Strategically placed hardfacing material near the shank end of a drill bit above the transition edges provides additional protection for compensator areas and the upper leg surfaces of drill bits during updrilling and/or backreaming operations. The strategically located hardfacing is typically passive in the normal drill mode, but active in the updrill drilling mode and/or back reaming. Alternative designs including other strategic material placement, the formation of hardfacing materials in tooth/wear design shapes, bimetallic gage, graded composite hardfacing materials, recesses or cavities at edges of the outer diameter, and various methods of applying the material also may be employed.

Abstract: A drill bit having steel teeth is provided with a combination of hardfacing materials on the teeth. The bases of the teeth are hardfaced with nickel-based materials to significantly reduce any potential cracking therein. Portions of the supporting cones adjacent the teeth also may be fabricated with the nickel-based hardfacing. All other portions of the teeth are hardfaced with iron-based materials.

Abstract: A drill bit having steel teeth is provided with a combination of hardfacing materials on the teeth. The bases of the teeth are hardfaced with nickel-based materials to significantly reduce any potential cracking therein. Portions of the supporting cones adjacent the teeth also may be fabricated with the nickel-based hardfacing. All other portions of the teeth are hardfaced with iron-based materials.

Abstract: Strategically placed hardfacing material near the shank end of a drill bit above the transition edges provides additional protection for compensator areas and the upper leg surfaces of drill bits during updrilling and/or backreaming operations. The strategically located hardfacing is typically passive in the normal drill mode, but active in the updrill drilling mode and/or back reaming. Alternative designs including other strategic material placement, the formation of hardfacing materials in tooth/wear design shapes, bimetallic gage, graded composite hardfacing materials, recesses or cavities at edges of the outer diameter, and various methods of applying the material also may be employed.

Abstract: An earth boring bit has at least one rotatable cone with a gage surface that engages a sidewall of a wellbore as the bit rotates. The gage surface has hardfacing bars spaced circumferentially apart from each other. A first group of the hardfacing bars extends from the inner edge of the gage surface to gage sides of the heel row cutting elements. A second group of the hardfacing bars extends from the inner edge of the gage surface to spaces between the heel row cutting elements, forming trimmer cutting elements. The hardfacing bars are made up of carbide particles in a metallic matrix.

Abstract: An earth-boring bit has a bit body, at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body, and a cutter mounted for rotation on the bearing shaft. The cutter includes a plurality of teeth that are covered with a hardfacing layer. At least some of the teeth have a leading side that has a streamlined contour. The streamlined contour is generally conical in some of the embodiments. In others, the streamlined contour is defined by a corner between diverging inner and outer sections of the leading side.

Abstract: An earth-boring bit has a bit body, at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body, and a cutter mounted for rotation on the bearing shaft. The cutter includes a plurality of teeth that are covered with a hardfacing layer. At least some of the teeth have a leading side that has a streamlined contour. The streamlined contour is generally conical in some of the embodiments. In others, the streamlined contour is defined by a corner between diverging inner and outer sections of the leading side.

Abstract: An earth-boring bit has rolling cutters, each attached to a bit leg depending from a bit body. Each of the cutters has hardfaced, milled teeth. A spear point is located on one of the cutters. The spear point has a neck that protrudes toward the axis of the bit from a conical portion of the cutter. Blades are located on the spear point with spaces located between the blades. A layer of hardfacing is applied to the entire spear point area including the blades, the spaces and the neck.

Abstract: An earth-boring bit has a bit body with at least one earth disintegrating cutter mounted on it. The cutter is generally conically shaped and rotatably secured to the body. The cutter has a plurality of teeth formed on it. The teeth have underlying stubs of steel which are integrally formed with and protrude from the cutter. The stubs have flanks which incline toward each other and terminate in a top. A carburized layer is formed on the flanks and the top to a selected depth. The stub has a width across its top from one flank to the other that is less than twice the depth of the carburized layer. A layer of hardfacing is coated on the tops and flanks of the stub, forming an apex for the tooth.