ITM High Speed Steel Drill Bit 2 Steps, 7/8" - 1-1/8" The further the bit advances, the larger the diameter of the hole gets. The self starting tip eliminates the need for pilot holes. M2 HSS Fast Spiral Flutes. For use with 1/4" Impact drivers 3/8 In drills and 1/2 " drills. 1/4" HEX power groove shank.