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 (martensite). The result is a product that is more consistently hard throughout, resulting in life up to 50% longer than the competition. (1) 5/8 in. Ice Hardened Hole Saw FEATURES Ice Hardened cryogenically treated for up to 50% longer lifeOptimized tooth form for up to 2X faster cuttingWide, angled & offset slots for easy plug accessBi-metal construction with 8% cobalt for increased wear resistanceWorks with the following arbors: 49-56-7210, 49-56-6950, 49-56-7000 & 49-56-7010 SPECIFICATIONS Hole Diameter 5/8 in.RPM Mild Steel 550RPM Stainless Steel 275RPM Cast Iron 365RPM Aluminum 825