US Patent 9303511 Flat cutter bit with cutting insert having edge preparation

A flat cutter bit for engaging an earth strata material includes a non-rotatable shank portion, a head portion integrally formed with the non-rotatable shank portion and including a tip region distal from the non-rotatable shank portion, and a cutting insert mounted at the tip region of the head portion. The cutting insert includes a body having an angled leading face, a top surface having a relief surface, a T-land surface extending between the angled leading face and the relief surface of the top surface and a cutting edge formed at the intersection of the T-land surface and the relief surface of the top surface.