Patent ID: 7195321

Claim:
The combination comprising: a tool having a tapered forward cutting end, a rearwardly facing radial flange at a rear of said tapered forward cutting end, said radial flange having a diameter defining a first dimension, and a cylindrical shank extending axially rearward of said radial flange, a tool holder having a forward surface, a cylindrical bore opening in said forward surface, an outer surface intersecting said forward surface wherein diametrically opposing portions of said intersecting surfaces define a second dimension, a wear ring on said shank between said radial flange and said forward surface, said wear ring having a non-circular outer perimeter having a first width defining a third dimension and a second width defining a fourth dimension, said third dimension is less than both said first dimension and said second dimension wherein a spacing remains between a portion of said flange and a portion of said forward surface, said fourth dimension at least equal to said second dimension, a retaining sleeve around said cylindrical shank and within said cylindrical bore for retaining said shank within said bore, and a lock between said wear ring and said sleeve wherein said wear ring is locked against rotation with respect to said forward surface solely by slid sleeve and an orientation of said wear ring with respect to said forward surface is random.