Abstract

The cutting action of a twist drill is very complex. This paper describes an investigation of this complex phenomenon through use of a quick-stop technique to freeze the action. The formation of chips, both along the cutting edges and under the chisel edge, is considered. Chip-flow angles, measured experimentally, are related to effective rake angle along the cutting edges, using a new derivation of the normal rake angle for a twist drill. The effects of point angle, drill design, and workpiece material are considered. The split (crankshaft) point for heavy web drills is investigated and its operation described.

This content is only available via PDF.
You do not currently have access to this content.