Irwin Tools Unibit #20 9/16-Inch to 1-Inch Step-Drill Bit, 1/2-Inch Shank (10220)
Get it all done with one when you choose Unibit stairstep bits. Single-flute cutting edge provides precise depth control though all size steps. Shanks flat side surface ensures slip-free chuck lock-down. Blunt-tip, hole-enlarging bit may be used on stainless steel, copper, brass, aluminum, plastic, laminates and wood. Materials: Steel Drill Bit Range Min: 1/2quot; Drill Bit Range Max: 1quot;.