Unique Bargains Woodwork Spiral Bit Twist Drill 5/16 Hollow Mortising Chisel

The square chisel mortiser combines the cutting of a four-sided chisel with the action of a drill bit in the center The bit clears out most of the material to be removed and the chisel ensures the edges are straight and clean. Hollow Mortising Chisel Bits are for making square mortises in one stroke and oblong mortises with each succeeding stroke.