Spiral-flute bits combine a shearing action in cutting with an augering action in chip clearance. The shearing action yields an especially clean accurate cut while the augering action clears chips from the cut. The ‘Up-Cut’ shears from the bottom up pulling chips from the bottom up thus allowing deeper penetration with less stress on the tool. An excellent choice for mortising.

These Mortise heads are designed to screw down onto a Helix Mortise Arbor for easy transition from one cutting head to the next.