XtremepowerUS Titanium Step Drill Bit - 1/4" to 1-3/8" in 1/8" Increments, 10 Steps Drills Sizes: 1/4" to 1-3/8" in 1/8" Increments Two Flute Design For Faster, Smoother Cutting Ten Sizes With Just One Bit For Drilling Holes in Thin Material Such as Steel, Stainless Steel, Copper, Alum Self-Starting, No Walking & Center Punch is Not Required