Super Sawzall blades are made with Matrix II high speed steel teeth containing 8% Cobalt to keep a sharper tooth edge longer. The tough Bi-Metal design allows faster cutting, longer life blades that can bend without shattering. Materials, tooth configuration and heat treating are designed to maximize performance in specific cutting applications. Durable, long life blades are the goal of every blade we make. All purpose blade for cutting all woods, nail embedded woods, composition material, plastic, ferrous and non-ferrous metals.