Drill multiple sized holes with one bit with the Greenlee 34403 step bit; no pilot hole needed. Steam oxide finish. For use on metal, steel, copper, brass, aluminum, wood, plastic, and laminates. Unique split tip design. Double flute construction. Maximum material size: 10 gauge.Chuck size: 3/8″. Length: 3 9/16″.12 Holes: 3/16″, 1/4″, 5/16″, 3/8″, 7/16″, 1/2″, 9/16″, 5/8″, 11/16″, 3/4″, 13/16″, 7/8″.