Irwin (928) 10220 IRWIN Unibit High-Speed Steel Fractional Self-Starting Step Drill Bit, No.20 (10220)

10220. Unibit® High Speed Steel Fractional Step Drill. No.20 9/16" - 1" (Hole Enlarging) - Carded. Standard Features: Single-flute cutting edge for greater control through steps. 3 flatted shank prevents slipping in drill chuck. Also available with (TiN) coating for longer life. Patented single-flute cutting edge gives the user a true round hole every time. Ideal for drilling holes into thin materials such as stainless steel, copper, brass, aluminum, plastic and laminates. Pilot hole required. Description: No.20. Hole Sizes: 9/16" - 1" (1/16" Increments, Hole Enlarging). Number of Holes: 8 steps. Hex Shank Size: 7/16".