US Patent 7665234 Grader blade with tri-grade insert assembly on the leading edge

A grader blade includes a grader blade body that has a recess in a bottom edge, and a tri-grade insert assembly is received within the recess. The tri-grade insert assembly includes a leading insert, a mediate insert and a trailing insert. The leading insert has an impact wear resistance and fracture wear resistance greater than the mediate insert and the trailing insert. The trailing insert has an abrasion wear resistance and down-pressure wear resistance greater than the leading insert and the mediate insert. The mediate insert has 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.