A method of manufacturing an earth-boring tool to reduce a carbon footprint of the earth-boring tool includes calculating an amount of CO.sub.2 associated with forming a drill bit. The method additionally includes redesigning the drill bit to reduce the amount of CO.sub.2 associated with forming the drill bit. The method may further include forming the redesigned drill bit. Related drill bits with reduced carbon footprints are also described.

A downhole cutting tool includes a tool body with a cutting element or cutting element pocket thereon. At least a portion of the tool body or an attachment thereto is a metal matrix composite formed from metal carbide particles dispersed in a continuous metal matrix. The metal carbide particles make up less than 45 wt % of the metal matrix composite and/or less than 30 vol % of the metal matrix composite. The continuous metal matrix may also be formed from a metal or metal alloy other than Ni—Si—B and/or have a transverse rupture strength greater than 150 ksi and a fracture toughness over 22 ksi*in.sup.0.5.

A downhole cutting tool includes a tool body with a cutting element or cutting element pocket thereon. At least a portion of the tool body or an attachment thereto is a metal matrix composite formed from metal carbide particles dispersed in a continuous metal matrix. The metal carbide particles make up less than 45 wt % of the metal matrix composite and/or less than 30 vol % of the metal matrix composite. The continuous metal matrix may also be formed from a metal or metal alloy other than Ni—Si—B and/or have a transverse rupture strength greater than 150 ksi and a fracture toughness over 22 ksi*in.sup.0.5.

A drill bit is provided that includes a bit body having one or more blades extending therefrom, a plurality of cutters secured to the one or more blades, and a rolling element assembly positioned within a cavity defined on the bit body. The rolling element assembly includes a rolling element rotatable within the cavity about a rotational axis, and a compliant retainer extendable within a retainer slot defined in the cavity to secure the rolling element within the cavity. The compliant retainer and the cavity cooperatively encircle more than 180° but less than 360° of a circumference of the rolling element while leaving a full axial width of the rolling element exposed. The compliant retainer is compressible responsive to forces from the rolling element to absorb vibrations and/or automatically adjust depth of cut.

A drill bit is provided that includes a bit body having one or more blades extending therefrom, a plurality of cutters secured to the one or more blades, and a rolling element assembly positioned within a cavity defined on the bit body. The rolling element assembly includes a rolling element rotatable within the cavity about a rotational axis, and a compliant retainer extendable within a retainer slot defined in the cavity to secure the rolling element within the cavity. The compliant retainer and the cavity cooperatively encircle more than 180° but less than 360° of a circumference of the rolling element while leaving a full axial width of the rolling element exposed. The compliant retainer is compressible responsive to forces from the rolling element to absorb vibrations and/or automatically adjust depth of cut.

A drill bit (11) for the drilling, in particular the rotary percussive drilling, of a hole, in particular a tap hole of a melting furnace, the drill bit (11) comprising a drill head (10), which has at least one hard material insert (16), and a base body (12) for connecting the drill bit to a driving element, the hard material insert (16) being inserted into a seat, which is formed in an axial end face (13) of the drill head (10), in such a manner that at least a head cutting edge (18) of the hard material insert (16) protrudes beyond the axial end face (13), wherein the seat has a flank portion and a mating flank portion located opposite the flank portion, between which the hard material insert (16) is disposed, the flank portion, which is disposed opposite a recess formed in the hard material insert (16), being provided with a material projection (35) which is at least partially made of a welding material, is bonded to the drill head (10) via the welding material and protrudes into the recess so as to establish a form-fitting connection with the hard material insert (16).

A drill bit (11) for the drilling, in particular the rotary percussive drilling, of a hole, in particular a tap hole of a melting furnace, the drill bit (11) comprising a drill head (10), which has at least one hard material insert (16), and a base body (12) for connecting the drill bit to a driving element, the hard material insert (16) being inserted into a seat, which is formed in an axial end face (13) of the drill head (10), in such a manner that at least a head cutting edge (18) of the hard material insert (16) protrudes beyond the axial end face (13), wherein the seat has a flank portion and a mating flank portion located opposite the flank portion, between which the hard material insert (16) is disposed, the flank portion, which is disposed opposite a recess formed in the hard material insert (16), being provided with a material projection (35) which is at least partially made of a welding material, is bonded to the drill head (10) via the welding material and protrudes into the recess so as to establish a form-fitting connection with the hard material insert (16).

A metal-matrix composite tool includes a matrix region. The matrix region has a reinforcement material, an outer surface, and an inner, localized area spaced apart from the outer surface within the reinforcement material. The reinforcement material has a reinforcement density and the localized area has a localized density different from the reinforcement density. The matrix region has an overall matrix density different from both the reinforcement density and the localized density.

A metal-matrix composite tool includes a matrix region. The matrix region has a reinforcement material, an outer surface, and an inner, localized area spaced apart from the outer surface within the reinforcement material. The reinforcement material has a reinforcement density and the localized area has a localized density different from the reinforcement density. The matrix region has an overall matrix density different from both the reinforcement density and the localized density.

A well drilling bit for drilling bedrocks includes a columnar bit body, and a drilling fluid flow path formed in the bit body to wash away drilled cuttings from a bottomhole and/or a periphery of the bit body. The flow path is provided with a venturi mechanism including a venturi tube having a reduced-diameter portion where a cross sectional area is reduced and capable of generating a decompression region around a tip of the bit body, the decompression region being more decompressed than a surrounding by the Venturi effect.