HELICAL DRILL BIT WITH LUBRICATION HOLES

摘要

The invention relates to a helical drill bit that includes, in series, a shank (10) for driving said drill bit, a main body (11) comprising at least two helical cutting elements (12) separated by helical grooves (19, 20), and a tip (14) including at least two cutting edges (15). According to the invention, on one portion of said main body (11), referred to as a lap portion (21), the helical cutting elements (12) have a tooth thickness e2 lower than the tooth thickness e1 of the helical cutting elements (12) in the rest of the main body (11) in order to increase the volume of said helical grooves (19, 20) in said lap portion (21).