Irwin 11105ZR Unibit5M 5-Millimeter to 35 -Millimeter by 1/2-Inch Shank Step Drill Bit
New SpeedPoint tip provides 6X faster initial penetration time than before, and eliminates the need for center punching. Single-fluted cutting edge assures true round holes, and allows greater control with less vibration. Ideal for drilling holes in thin materials such as mild steel, copper, brass, aluminum, plexiglass, wood, and laminates.