This is a Whiteside spiral upcut bit, model RU2075R, ground for clean upcut mortising and slotting that clears chips upward. It measures 1/4″ cutting diameter, 1/4″ shank, 1/8″ radius, and uses carbide cutting edges that resist heat and hold an edge far longer than plain steel.
Chuck it into a router table or handheld router to cut mortises, clean slots, and dadoes where chip ejection keeps the cut cool. The balanced bit runs true at speed, so cuts come out concentric and clean with minimal sanding afterward.
Whiteside Machine Company manufactures its router bits in Claxton, Georgia, and is consistently rated among the top-performing router bit makers in independent woodworking tests.









