Irwin Unibit HSS Fractional Hole Enlarging #21- (PV10221)

Single-flute cutting edge for greater control through steps. 3 flatted shank prevents slipping in drill chuck. Also available with titanium nitride 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.