Designed with a robust 1/4 in quick-change hex shank, Milwaukee SHOCKWAVE Impact Duty thin wall hole saws give professionals a hole making solution to use with impact drivers. Utilizing a thin wall, 8 TPI design, thin wall hole saws deliver a burr-free cut up to 40% faster than standard bi-metal hole saws. The included ejection spring removes the frustration of manually removing slugs by automatically ejecting the material. A stop shoulder design prevents over drilling into material and potentially damaging inner components of electrical and junction boxes. Choose thin wall hole saws for use in plastics and thin gauge metals up to 1/8 in thick.1/4 in quick-change hex shank for use with impact driversStop shoulder design prevents over drilling and damaging componentsThin wall 8 TPI design for 40% faster cuts than standard bi-metal hole sawsEjection spring automatically removes slugs