Milwaukee 49-56-0217 4-1/8" Hole Dozer Bi-Metal Hole Saw

Includes:
(1) 4-1/8 in. Ice Hardened Hole Saw Features
Ice Hardened cryogenically treated for up to 50% longer life Optimized tooth form for up to 2X faster cutting Wide, angled & offset slots for easy plug access Bi-metal construction with 8% cobalt for increased wear resistance Works with the following arbors: 49-56-7240, 49-56-7250, 49-56-9100, 49-56-7055, 49-56-7040, 49-56-7140 & 49-56-7150 SPECIFICATIONS: Hole Diameter: 4-1/8 in. RPM Mild Steel: 80 RPM Stainless Steel: 40 RPM Cast Iron: 55 RPM Aluminum: 120 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