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. Features optimized tooth form for up to 2 times faster cutting, wide, angled and offset slots for easy plug access, and bi-metal construction with 8% cobalt for increased wear resistance. For use with steel, non-ferrous metals, wood, plastic. Set includes 6 holes saws (3/4", 7/8", 1-1/8", 1-1/2", 1-3/4", 2-1/4"), 2 arbors with pilot bits (49-56-7010, 49-56-9100), 2 drill bits (49-56-8010), adapter (49-56-6560), spacer (49-67-0102), carrying case. No. 49-22-4145: Material: Bi-Metal, Pieces In Set: 10 Pcs., Pkg Qty: 1, Package Type: Sleeve