Malco’s UB1, UB3, UB11, and UB20 Step Drills offer a unique double flute design to ensure the penetration of soft or thin materials at the proper speed. These step drills, drill hole sizes from 1/8″ to 1″ through 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. Each drill is made of industrial grade high speed steel and are heat treated and tempered to ensure maximum strength for long wearing rugged use. All step drills from Malco are able to be resharpened for longer use.