These are quality bits made to exacting standards in Japan. Self feeding bits feature a replaceable lead screw that feeds the bit into the work piece at a consistent rate. Excellent choice when you need to drill big holes free-hand as the lead screw prevents the bit from wandering. Do not use these bits in a drill press. Overall length for the bits are 4 5/8" with a 7/16" hex shank. Several quality features set these bits apart from the rest:
Teeth have a wider cutting surface for stability and truer holes.
Chamfered back edge for easier extraction of the bit from the work.
Lead screw has burr-free threads for a consistent feed rate.
Absolutely straight shaft for superior concentricity and zero wobble.
Quick-change shank for fast and secure change-out.
Machined from properly heat treated and hardened high carbon steel for extended durability.