Tool bit with axially extending grooves in insertion end

Abstract From the Canadian patent

A tool bit has a shank with an axially extending insertion end for insertion into a chuck on a drive unit. The insertion end has closed ended axially extending grooves and axially extending grooves open at the trailing end of the insertion end. The open end grooves have a base with a shaped configuration. The shaped base has depressions or recesses forming stop faces extending transversely of the axial direction and acting essentially in the axial direction of the insertion end. When the insertion end is placed into the chuck, any dirt on the stop faces can be wiped off and deposited in the recesses. The shaped configuration of the base prevents, during formation of the axially elongated …