A method for producing a cutting tool such a twist grill, end mill, or the like. The method provides an unbonded assembly including a cylindrical core having ends and an elongate side surface covered partially or completely by a coherent, unsintered layer including ultra-hard abrasive particles for producing an ultra-hard material. The unbonded assembly is subjected to elevated temperature and pressure conditions at which the ultra-hard abrasive is crystographically stable. The sintered product is then recovered that includes a cylindrical core and a layer of ultra-hard abrasive material bonded to the core, and the sintered product is worked to produce one or more cutting edges in the layer of ultra-hard abrasive material.

A cutter comprising a superabrasive volume including a cutting face portion extending transversely across a leading face of a supporting substrate and a contiguous jacket portion extending rearwardly over the supporting substrate along a portion of its side periphery. Interfaces between the respective superabrasive volume cutting face and cap portions and adjoining surfaces of the supporting substrate are each irregular. The leading face of the substrate includes grooves extending toward the jacket at least partially across the leading face from the side of the substrate opposite the jacket. The side periphery of the substrate defining the location of the jacket is grooved at a plurality of laterally-adjacent locations with substantially axially-oriented grooves extending rearwardly from the leading face of the substrate to a position closer to the trailing face of the substrate. At least one ridge intermediate the side grooves may not extend radially outwardly to a full diameter of the substrate so that the superabrasive material of the jacket extends not only into the circumferential grooves but also circumferentially therebetween, providing a continuous, arcuate superabrasive surface which may have substantially the same exterior diameter as that of the substrate itself. Rotary drill bits for subterranean drilling bearing cutters according to the present invention are also disclosed.

A rotary drill bit having a plurality of circumferentially spaced gage pads for drilling bore holes of a preselected trajectory, including lateral or deviated bore holes, in subterranean formations. Each gage pad is provided with, or alternatively associated with, at least one aggressive gage, or side, cutting element having a preselected relative degree of aggressiveness. Selected circumferentially spaced gage pads comprise at least one gage cutting element, or cutting region, disposed thereon and/or comprise alternative gage-cutting elements longitudinally proximate and exclusively associated with a selected gage pad. At least one such gage-cutting element provides more aggressive gage-cutting than at least one other, less aggressive gage-cutting element disposed on, or associated with, a different gage pad. Each of the more aggressive gage pads and each of the less aggressive gage pads may be positioned about the drill bit in a wide variety of circumferential patterns including, but not limited to, an every other alternating gage pad aggressivity pattern. A further optional circumferential gage pad alternation pattern includes, but is not limited to, a first plurality of gage pads having a generally similar first level of aggressiveness being placed proximate and circumferentially adjacent each other on a selected side of the drill bit, with the remaining second plurality of gage pads having a generally similar second level of aggressiveness being placed proximate and circumferentially adjacent each other on the opposite side of the drill bit. Drill bits embodying gage-cutting elements of more than two levels or degrees of aggressivity are also disclosed.

A cutting element includes a layer of integrally bonded superabrasive particles disposed over a substrate. The layer has an outer circumference comprising at least one trough having a distinct cutting point on either side of the trough. A rock drilling drag bit incorporating the cutting element and a method of cutting a material using the cutting element are also disclosed.

A superabrasive cutting element for use with a drill bit for drilling subterranean formations and having a superabrasive table, or cutting face, in which a conglomerate of superabrasive particles is dispersed and bonded, or sintered, and in which at least one exposed cutting region of the superabrasive table develops a rough, asperital surface for improving the cutting efficiency of the drill bit, particularly in but not limited to relatively hard, relatively nonabrasive formations. The superabrasive table may include superabrasive particles of substantially differing size, or quality or a combination of differing size and quality. A rotary drill bit including cutting elements embodying the present invention is also disclosed.