Patent ID: 7665234

Claim:
A grader blade comprising: a grader blade body having a recess contained in a bottom edge; a tri-grade insert assembly received within the recess, and the tri-grade insert assembly comprising a leading insert, a mediate insert and a trailing insert; and wherein the leading insert having an impact wear resistance and fracture wear resistance greater than the mediate insert and the trailing insert, the trailing insert having an abrasion wear resistance and down-pressure wear resistance greater than the leading insert and the mediate insert, and the mediate insert having an impact wear resistance and fracture wear resistance greater than the trailing insert and an abrasion wear resistance and down-pressure wear resistance greater than the leading insert and wherein the leading insert, the mediate insert and the trailing insert each comprise cemented (cobalt) tungsten carbide, and the leading insert has a higher cobalt content than the mediate insert and the trailing insert, and the mediate insert has a higher cobalt content than the trailing insert; and wherein the leading insert having a height greater than the height of the mediate insert and the trailing insert, and the mediate insert having a height greater than the height of the trailing insert.