Product Description BOSCH SDS-max carbide-tipped rotary hammer core bits offer an integral shank for better power transmission. BOSCH SDS-max rotary hammer core bits with wave design go beyond the range of standard bits and allow smaller hammers to drill larger holes. Wave design transfers energy to bit more effectively for up to 40 percent faster drilling versus previous design. From the Manufacturer The Bosch HC8540 SDS-max shank 1-piece core bit measures 3-1/2-inches in diameter, 7-inches in useable length, and 12-inches in total length. Bosch core bits go beyond the range of standard bits and allow smaller hammers to drill larger holes. Bosch SDS-max rotary hammer core bits are carbide tipped with an integral shank for better power transmission. The maximum core size is 4 deep. The Robert Bosch Tool Corporation is one of the largest power tool and accessory manufacturers in the world. Bosch provides a complete line of corded and cordless power tools and accessories engineered to survive any jobsite and allow professionals to take control of their work.