High Performance Drill Point Angles
Why do high performance drills all have points in the 130º-150º range instead of 118º points?
As a general rule harder materials are drilled with 130º to 150º points and softer materials like wood, hard rubber, plastics, and fibers are drilled with 90º to 100º points. 118º points are somewhat in the middle and are considered to be more general-purpose type points.
High performance drills are generally used in more difficult to machine materials like alloys steels, stainless steels and high temperature alloys. These materials are more effectively cut with points that produce thicker chips. Drills with 130º to 150º points have shorter cutting lips, which do produce thicker chips for a given feed rate. These thicker chips also reduce the tendency of these materials to work harden. Torque requirements are also reduced with higher points angles.
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