This is a Whiteside keyhole bit, model 3051, ground for routing keyhole slots for flush hanging. It measures 7/16″ cutting length, 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 keyhole slots so frames and signs hang flat against the wall. 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.
