METAL CUTTING DRILL CONTAINING INSERTING BODY HAVING RADIUS DIRECTIONAL OVERLAPPED CUTTING BLADE

摘要

PURPOSE: A metal cutting drill including an inserting body hard soldered on the main body of the drill and a main body is provided to get rid of the tendency that the drill is corroded and damaged. CONSTITUTION: The drill(40) includes a head(44) that the main body of the drill is placed on a hollow shank(42) and on the front end part of the shank. Herein, the shank communicates with a pair of big and small throat units(48, 50) which converge to a rear part from the front face of the shank and has a central coolant passage(46) extended to the front part in a shaft direction from the rear end part of the shank. The cutting inserting body(60) hard soldered within a recess formed within the front(52) includes the main body formed as an initial hardening material instead of a steel drill main body.