Tough, flexible steel back and Matrix II steel with 8% cobalt cutting edge give maximum durability. Angled shank for faster cutting. Universal shank. Includes 1 each of the following 6" blades: wood cutting 6 TPI tapered back, wood cutting 10 TPI straight back, metal cutting 14 TPI straight back, metal cutting 18 TPI straight back, metal cutting 24 TPI straight back, and wood cutting 5/8 TPI straight back.