Covering a range of sizes, these adjustable boring bits will take away the need to have lots of drill bit sizes in your tool box. The size can easily be set with the movable cutter that has graduations etched into it, the cutter is then locked. The outer scribe cuts a clean splinter-free edge whilst the centre point helps to hold the drill accurately and the cutter provides a shearing action to remove waste very effectively. They can leave a flat bottomed hole or go straight through your work. Suitable for hard and soft wood for use in a cordless or mains tool and when working on a lathe. 34-80mm, 1/2" shank, 115mm effective drilling depth, 157mm overall length.