Ice Hardened blades are processed with a cryogenic heat treatment so they can handle the toughest alloy steel materials. A unique combination of relief angles forms a radius on the back of the tooth that reduces stress build-up during cutting and substantially extends blade life. Precision forming process creates sharper teeth for fast cutting. No. 48-00-4091: Length: 6 In., Teeth Per Inch: 8/12 TPI, Type: Ice-Hardened Multi-Material, Material: Bi-Metal, Application: Wood,Nail-Embedded Wood,Plastic,Metal, Pkg Qty: 5, Package Type: Clamshell No. 48-00-4093: Length: 8 In., Teeth Per Inch: 8/12 TPI, Type: Ice-Hardened Multi-Material, Material: Bi-Metal, Application: Wood,Nail-Embedded Wood,Plastic,Metal, Pkg Qty: 5, Package Type: Clamshell