Microcutting of steel using pyramidal diamonds with different apex angles

The microcutting of steel with pyramidal diamond points was performed in the speed range 5–55 m s^?1. The apex angles of the diamonds were 90°, 110°, 130°, 150° and 170°. It was found that the material removal mechanism for the diamonds with apex angles 150° and 170° differed from the mechanism for the sharper diamond points. The latter points showed a standard chip formation cycle whereas the two blunter points probably removed material by an extrusion mechanism.