Milwaukee's® ¼” x 1-1/2" Shockwave Impact Duty™;;; Thin Wall Hole Saws utilize an 8 TPI design. The thin wall hole saws delivers a burr-free cut faster than standard bi-metal hole saws. The included ejection spring removes 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. Thin wall hole saws are great for use on plastics and thin gauge metals up to 1/8” thick.