Step Drill 8 Hole Sizes in 9/16" increments. A unique double flute design assures the penetration of soft or thin materials at the proper speed. Drill hole sizes from 1/8" to 1" in sheet metal without burring or deforming stock or threading drill bit. Malco Step Drills actually de burr as they drill. Perfect for use as a "hole-opening" reamer. They can also be used for making round holes from slots or intersecting holes. Made of industrial grade high speed steel. Malco Step Drills are heat treated and tempered to assure maximum strength for long wearing rugged use. Completely resharpenable.