Use in log furniture construction to cut a precise 60 deg. taper on the mortisea perfect match when used in conjunction with the 60deg. tenon cutterfor a strong, beautiful joint. Drill a 1", 1-1/2", or 2" diameter hole with a forstner bit, then use this countersink bit (with the appropriate guide bore) to create a perfectly shaped shoulder. Set includes the triangular blade, a 1" diameter shaft, 1-1/2" and 2" guide bores, and an allen wrench for assembling the bit and changing bores. 1/2" shank. For use with Log Tenon Cutters.