Irwin (928) 10221 10221 - STEP DRL No.21 13/16-1-3/8" 10 SZ

10221 Unibit® High Speed Steel Fractional Step Drill. No.21 13/16" - 1-3/8" (Hole Enlarging). 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.21. Hole Sizes: 13/16" - 1-3/8" (1/16" Increments, Hole Enlarging). Number of Holes: 10 steps. Hex Shank Size: 7/16".