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.

Fits slots cut by all standard plate joiners. Compressed beech wood. Swells when used with water-based glues to "lock" joints.