Abstract: With conventional small troublesome indexable inserts from high-pressure sintered materials having neither a screw-hole nor a cavity for attaching the insert to a toolholder, clamping the insert onto the holder has been complicated and the tightening force has been weak. The cause behind this is that with the hardness of high-pressure sintered material being high, surface machining is extremely difficult. A toolholder attachment cavity is provided in the rake face of an indexable insert composed of a high-pressure sintered material, by machining with a laser whose light output power is adjusted and whose light-harvesting is enhanced using a galvanometer mirror, while high-precision controlling the beaming position. This allows small-scale indexable insert of high-pressure sintered material to be mounted onto a holder simply and securely with a clamp, and makes for curtailed prep time, improved machining precision, and better mounting reliability.

Abstract: A tip-changeable rotary cutting tool in which a tip having axis-symmetrically arranged cutting edges is inserted into a groove that cuts across the center of the holder's front end is improved in machining precision, product precision, and machining performance. Forward-facing oblique locking faces 8 are provided axis-symmetrically at the front ends of jaws 3 of a holder 1. The locking faces 8 cross each other at a position a certain distance (one-third to two-thirds the width of the tip) away from the front end of the tool to lock backward-facing engaging faces 9 provided at some longitudinal midpoint position of a tip 5. The shortened distance between the cutting edge 6 and the locking position suppresses the runout deviation of the tip, decreasing the displacements of the cutting edges due to the runout deviation. A large chip pocket can also be provided.