Super SAWZALL blades are made with Matrix II high speed steel teeth containing 8% cobalt to Keepa sharper tooth edge for a longer lasting and more durable use. The tough bi-metal design allows for faster cutting, sturdier blades that can bend without shattering. Milwaukee designs and manufactures SAWZALL blades for the toughest professional applications. Materials, tooth configuration and heat treating are designed to maximize performance in specific cutting applications. This 5-pack of 9 in. 5 TPI SAWZALL Reciprocating Saw Blades have a 1/2 in. universal tang that fits all SAWZALL and standard competitive saws.