Patent ID: 8205692

Claim:
An insert for a drill bit comprising: a base portion; a cutting portion extending from the base portion, wherein the cutting portion includes a pair of flanking surfaces that taper towards one another to form an elongate chisel crest having a peaked ridge; wherein the elongate chisel crest extends between a first crest end and a second crest end, and has an apex positioned between the first and second crest ends, the apex defining an extension height for the insert; wherein a transverse cross-section at the apex has an apex transverse radius of curvature, a transverse cross-section at the first crest end has a first crest end transverse radius of curvature that is less than the apex transverse radius of curvature, and a transverse cross-section taken at the second crest end has a second crest end transverse radius of curvature that is less than the apex transverse radius of curvature; wherein the apex transverse radius of curvature is at least 10% larger than the first crest end transverse radius of curvature, and at least 10% larger than the second crest end transverse radius of curvature.