1/2" universal blade tang fits in all Sawzall®'s. Bi-metal construction increases blade life. Blades do not shatter. Super hard wear resistant high speed steel (tooth area) laser welded to a flexible spring steel backing material. Matrix II teeth with 8% cobalt. Blade Reversible in clamp. Matrix II High Speed Steel retains tooth hardness at high temperatures for metal cutting applications. Bi-metal construction allows the blade to flex and absorb impact without breaking while cutting nail embedded wood. 0.042" thick for stiffer performance and longer life. More aggressive blade removes more material per stroke for faster cutting. Metal 1/4" thru 3/8", channels, metal pipe, cast iron, demolition, rescue and remodeling.