These Bridge Pin Hole Countersink Chamfering Bits for Luther Workshop tools 5/Fluted 1/2" & 5/8 " for Acoustic Bridge with high speed steel 1/2" and 5/8” diameter countersinks for chamfering acoustic guitar bridge pin holes. Hi-quality 5 flute design for a very smooth and easy cut. 1/4" diameter shafts.

The bits eliminates the chance of chipping the pin hole and gives you precise consistent control. By starting with the 1/2" bit first then can following up with the 5/8 bit to get the size and depth of cut you want. That keeps the bevel round and more even on a curved bridge surface. You can use it with your hand drill or drill press for cleaner professional results. Then you can do the Pin Hole slots to stop String buzzing.  I sell the tool for that job to my 2 Blade in hole slotting tool!