Overview Reviews Product Description The Irwin 323015 drill bit, 7/8 x 17 x 21 SDS-MAX® 4 cutter masonry drill bit is a fast and durable bit for the professional user.The bit features a chrome vanadium spring steel shaft that is through-hardened for superior durability.The shot-peened, double tempered finish reduces breakage.The bit also features a tip with a copper brazed material that gives high heat resistance and reduced tip loss.The SDS-MAX® shank fits all SDS-MAX® rotary hammers.The four cutter tip provides more durability and rounder holes. Irwin Tools Catalog Product Videos Custom Field Manufacturing country DE Product Reviews Write a Review Write a Review × Irwin 7/8 x 17 x 21" 4-Cutter SDS-MAX® Hammer Drill Bit 323015 Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Review Subject * Comments *