Makita B-66634 1‘3/4" Rotary Hammer Core BitMakita B 66634 Makita Rotary Hammer Core Bits feature asymmetrical tungsten carbide teeth for faster drilling and longer life. Bit is part of a 2 piece core bit system that increases versatility and productivity. Core bits have larger diameters than standard carbide bits, allowing smaller hammers to drill larger holes. The bits are for dry drilling in concrete, block, and brick, and are ideal for drilling larger holes in masonry for piping,