Square Hole Mortise Chisel Drill Bit Tools, Woodworking Hole Saw Mortising Chisel Drill Bit Set Twist Drill, Different Sizes 1/4" 5/16" 3/8" 1/2" (4pcs)
- This square hole drill bit is great for drilling square holes in wood with a mortising machine or a mortising attachment..
- This mortising chisel fits all mortising machines and drill press attachments 6.4mm (1/4"), 8mm (5/16"), 9.5mm (3/8"), 12.7mm(1/2") sizes.
- The drill bits for square holes with high performance flute design geometry for superior chip extraction.
- Made of the highest quality tool steel Hardness: HRC 48~50.
- Used with mortising chisel , if extend square hole manually, need to use electric drill, hammer and other tools..