TAPPING TOOL FOR HOLES AS CAST.

摘要

Tapping tool used for machining holes as cast in castings. The tool has cutting edges (4a to 4d), a guide portion (3), a tapping portion (2) and a shank (1) extended to the tapping portion. The holes as cast are face-cut and drilled with said cutting edge to make holes before threading, then finished by reaming with said guide portion, and cut into female threads with said tapping portion. Highly accurate female threads can be made readily and rapidly, because of perfect alignment of the center line of the hole before tapping with that of the tapped hole.