Steel tooth bit with extra-thick hardfacing

An earth-boring bit comprising:

• a bit body;
• at least one earth disintegrating cutter, the cutter being generally conically shaped and rotatably secured to the bit body;
• a plurality of teeth formed on the cutter, at least one tooth of the teeth comprising:
• a steel stub integrally formed with and protruding from the cutter, the stub having a pair of flanks which incline toward each other relative to an axis of the tooth and terminate in a top;
• a carburized layer formed on the flanks and the top to a selected depth, the depth of the carburized layer being substantially uniform on all surfaces of the stub;
• the distance between the flanks, measured perpendicular to the axis at the top, being greater than twice the depth of the carburized layer;
• a layer of tube hardfacing coated on the top and flanks of the stub and forming an apex for the tooth;
• and
• wherein the stub has a length measured along the axis of the tooth from a root of the tooth to the top, and wherein the hardfacing has a thickness measured along the axis of the tooth from the top of the stub to the apex formed by the hardfacing, which is at least 15 percent of the length of the stub, the thickness of the hardfacing being at least {fraction (3/16)} inch.

An earth-boring bit comprising:

• a bit body;
• at least one earth disintegrating cutter, the cutter being generally conically shaped and rotatably secured to the bit body;
• a plurality of teeth formed on the cutter, at least one tooth of the teeth comprising:
• a steel stub integrally formed with and protruding from the cutter;
• a layer of tube hardfacing coated on the stub, forming an apex for the tooth, the hardfacing having carbide particles within a metal matrix, the matrix having a hardness after application of the hardfacing on the tooth and heat treating of at least 53 RC;
• and
• a carburized layer formed on the top of the stub;
• and
• wherein the hardfacing has a thickness measured along the axis of the tooth from the top of the stub to the apex formed by the hardfacing which is at least {fraction (3/16)} inch.

An earth-boring bit comprising:

• a bit body;
• at least one earth disintegrating cutter, the cutter being generally conically shaped and rotatably secured to the bit body;
• a plurality of teeth formed on the cutter, at least one tooth of the teeth comprising:
• a steel stub integrally formed with and protruding from the cutter for a length measured along an axis of the tooth from a root of the tooth to a top of the stub, the stub having leading and trailing flanks on opposite sides which incline toward each other relative to the axis, and inner and outer end surfaces, the flanks and the inner and outer end surfaces terminating at the top;
• a layer of tube hardfacing coated on the stub, forming an apex for the tooth, the hardfacing having carbide particles within a metal matrix, the matrix having a hardness after application of the hardfacing on the tooth and hardfacing of at least 53 RC;
• and
• wherein the hardfacing has a thickness measured along the axis of the tooth from the top of the stub to the apex formed by the hardfacing which is at least {fraction (3/16)} inch.