Woller bit
A drill bit for sheet metal that gets the same results as a knock out set only much quicker that when pointed up resembles a miniature hardened metal Christmas tree with an open shavings moving channel running vertically separating the leading horizontal cutting edges and the trailing chip clearing edges who's tips pointed down start at 1/8" -3/16" diameter and are tapered up from step to step that step in at 1/16" advancing increments and step up from level to level at 1/8" advancing increments until the maximum diameter is achieved usually 3/4" to 1-1/2" that carry the job of making smaller holes much bigger .
Woller bit by Tungtwistr January 17, 2022
