STEP DRILL BIT

摘要

A drill bit includes a shank, a transition portion, and a body portion defining a plurality of axially stacked, progressively sized steps. The steps include a first step and a terminal step coupled to the transition portion. The first step defines two tip flutes each disposed at a tip flute angle. The body portion defines two body flutes each extending from the first step to the transition portion and disposed at a body flute angle different from the tip flute angle. The drill bit includes a bit tip disposed at the distal end of the body portion and having a chisel edge, a first chisel surface on one side of the chisel edge, and a second chisel surface on an opposite side of the chisel edge. The first chisel surface defines a first relief angle. The second chisel surface defines a second relief angle different from the first relief angle.

主权项

1. A drill bit comprising:
a shank extending along a bit axis; a transition portion coupled to the shank; a body portion having a distal end and defining a plurality of axially stacked, progressively sized steps including a first step at the distal end and a terminal step coupled to the transition portion, the first step defining two tip flutes each disposed at a tip flute angle from the bit axis, the body portion further defining two body flutes each extending from the first step to the transition portion and disposed at a body flute angle different from the tip flute angle; and a bit tip disposed at the distal end of the body portion and having a chisel edge intersecting the bit axis, a first chisel surface being on one side of the chisel edge, and a second chisel surface being on an opposite side of the chisel edge, the first chisel surface defining a first relief angle, and the second chisel surface defining a second relief angle that is different from the first relief angle.