METHOD FOR DRILLING FREE CUTTING STEEL PRODUCT CONTAINING NO LEAD

摘要

PROBLEM TO BE SOLVED: To provide a method for drilling a free cutting steel product capable of improving the service life of a drill when deep drilling is performed for a free cutting steel product for a machine structure containing no Pb as a free cutting element. SOLUTION: In this method for drilling the free cutting steel product containing no lead, the drilling is performed by using the drill made of high- speed tool steel, and having 0.30 to 0.40 of the ratio (t/d) of web thickness (t) and a diameter (d), and 36 deg. to 40 deg. of an angle of torsion, and the surface of a groove part for which TiN coating or homogenizing treatment is performed.