This Milwaukee Ice Hardened 2-1/2 in. Hole Saw is made of high-speed steel and will cut various materials. It requires a minimum chuck size of 1/2 in. and has a 1-4/5 in. drilling depth. Milwaukee Ice Hardened products utilize a proprietary cryogenic hardening process that improves upon traditional heat treat processes. Unlike surface coatings that wear away, cryogenics harden to the core by minimizing soft metal (austenite) and creating more hard metal (marten site). The result is a product that is more consistently hard throughout, resulting in life up to 50% longer than the competition.