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. Material(s): Steel; Drill Bit Range [Min]: 1/2"; Drill Bit Range [Max]: 1".