Tangential Toolholder

[Hawkeye]

Tom, the bit is angled toward the work and toward the headstock. Both angles are typically 12*. Only the end of the tool blank is ground, at an angle of 30* diagonally. The effect of the combination of angles is a diamond with a narrow angle of about 85*.

If you set it up right, you can do both turning and facing operations without rotating the toolholder. It's a good idea to hone the long corner, the cutting corner, to a small radius, as with other types of cutters.

These things work so well that it's worth making one just to try it out.