A cutting element includes a base and a cutting face at opposite axial ends, a side surface extending between the base and the cutting face, an edge formed between the cutting face and the side surface, an edge chamfer having a uniform size around the entire edge, and a geometric shape formed on the cutting face and defined by a concave boundary with respect to a longitudinal axis of the cutting element. The concave boundary includes multiple rounded vertices, each rounded vertex located proximate to the edge chamfer and forming a cutting tip and multiple geometric shape sides connecting the rounded vertices, wherein the geometric shape sides are concave with respect to the longitudinal axis.

A drill bit for cutting formation comprises a bit body, a plurality of cutters, a plurality of blades with pockets to accommodate the cutters respectively. Each of the plurality of cutters has an ultra-hard layer, two side facets extending obliquely inward from the substrate to a top surface of the ultra-hard layer, a convex portion between the two side facets. The convex portion comprises a transition surface and the transitional surface is convex as it extends between adjacent the two side facets. The curvature of the transitional surface varies along the cutter axis with the curvature at the cutting edge larger than the curvature of the cutter circumferential surface.

A superabrasive element includes a substrate and a superabrasive table bonded to the substrate, the superabrasive table including a polished surface having a polished finish, the polished surface extending over at least a central, apical region of the superabrasive table, and an unpolished surface including an unpolished finish, the unpolished surface surrounding a majority of the polished surface. A method of manufacturing a superabrasive element includes providing a superabrasive element having a substrate and a superabrasive table bonded to the substrate and polishing at least a central, apical region of the superabrasive table to form a polished surface, without polishing an unpolished surface of the superabrasive table, the unpolished surface surrounding a majority of the polished surface.

A drilling tip includes a tip main body that has a posterior end portion having a columnar or disk shape centered on a tip center line and a distal end portion and is made of a cemented carbide and a hard layer that coats the distal end portion and is made of a polycrystalline diamond sintered body. The distal end portion has a convex portion, and a concave portion. A diameter D of the posterior end portion is 8 mm to 20 mm. A ratio r1/D of a radius r1 of the convex portion is 0.1 to 0.65, and a ratio r2/D of a radius r2 of the concave portion is 0.05 to 3.0. An angle formed by a straight line that connects a tangent point which the convex portion tangents to the concave portion and a center of the convex portion to each other is 20° to 90°.

A cutting element comprises a supporting substrate, and a cutting table attached to an end of the supporting substrate. The cutting table comprises inter-bonded diamond particles, and a thermally stable material within interstitial spaces between the inter-bonded diamond particles. The thermally stable material comprises a carbide precipitate having the general chemical formula, A.sub.3XZ.sub.n-1, where A comprises one or more of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, and U; X comprises one or more of Al, Ga, Sn, Be, Bi, Te, Sb, Se, As, Ge, Si, B, and P; Z comprises C; and n is greater than or equal to 0 and less than or equal to 0.75. A method of forming a cutting element, an earth-boring tool, a supporting substrate, and a method of forming a supporting substrate are also described.

A drill bit including a body having a face and a plurality of blades disposed on the face of the body. Each of the plurality of blades may have a row of cutters disposed thereon, and the rows of cutters may collectively define a cutting profile of the drill bit. At least some of the cutters along the cutting profile may have alternating positive back rake angles. The difference between a majority of back rake angles on adjacent cutters along the cutting profile may be less than 20°.

A cutter element for a drill bit includes a base portion having a central axis, a first end, and a second end. In addition, the cutter element includes a cutting layer fixably mounted to the first end of the base portion. The cutting layer includes a cutting face distal the base portion. The cutting face includes an elongate raised ridge having a first end at a radially outer surface of the cutting layer and a second end at the radially outer surface of the cutting layer. The raised ridge defines a maximum height of the cutter element measured axially from the second end of the base portion to the cutting face. The cutting face also includes a first planar lateral side surface and a second planar lateral side surface. Each planar lateral side surface extends from the raised ridge to the radially outer surface of the cutting layer.

A cutting element comprising a polycrystalline diamond table having a first end attached to a substrate at an interface. The second end of the diamond table includes a concave surface, concave indentations, cutting edges at an interface between the concave surface and an outer diameter of the diamond table. Each of the at least two concave indentations intersects the concave surface and extends radially outward from the concave surface to an outer diameter of the diamond table. A method of manufacturing an earth-boring downhole tool includes providing a tool body and securing to the tool body the cutting element as recited in any one of the claims.

Disclosed is a drill bit for cutting formation comprises a bit body, a plurality of cutters, a plurality of blades with pockets to accommodate the cutters respectively. Each of the plurality of cutters has at least one alignment structure to align with at least one counter-alignment structure on each of the pockets to locate the rotary orientation between each of the plurality of cutters and each of the corresponding pockets.

A cutting element includes a substrate configured to couple to a pocket formed in a blade of a downhole drill bit and a polycrystalline diamond portion secured to the substrate. The polycrystalline diamond portion includes a cutting face, a radial sidewall, and a cutting edge formed at a transition from the radial sidewall to the axial the cutting face. The cutting face includes a plow feature disposed at a center of the cutting face. The plow feature has a face portion and a shoulder portion. The shoulder portion extends radially outward from the face portion and axially downward toward the substrate. Additionally, the cutting face includes a recessed portion extending between the cutting edge and a radially outer edge of the shoulder portion.