HELICAL DRILL WITH REAMER (VERSIONS) Russian patent published in 2013 - IPC B23B51/02 B27G15/00 

FIELD: process engineering.

SUBSTANCE: invention relates to hand-held tools, particularly, to helical bit for drill. Said bit comprises long element, head, top part and shank. Long element comprises first end part and opposite second end part, and helical surface with central axis. Said helical surface defines at least one chip flute. Head is made integral with first end part of long element and comprises cutting edges. Top part with thread is made integral with said head. Shank is made integral with second end part of long element and is intended for joint with the drill. Said head additionally comprises transition part between primary cutting edge and secondary cutting edge. Transition part makes an angle with central axis. In compliance with the second version, said head comprises top part with thread, primary cutting edge and remaining part arranged behind the primary cutting edge. Besides, this bit is furnished with the part acting as a reamer including the secondary cutting edge and at least one transition section located between primary cutting edge and secondary cutting edge. In compliance with the third version, helical bit with reamer comprises long shank and enraged cylindrical head. Said head comprises helical feed part for pulling the bit into workpiece in drilling. Besides, the drill includes at least one chips flute, first, second and third parts.

EFFECT: higher quality of machining.

12 cl, 8 dwg