Also known as demolition blades, these wide blades cut through multiple layers. They're stiffer than other blades for making straight cuts in a wide range of materials including metal, plastic, and wood. Blades have a 1/2" universal shank that fits most reciprocating saws. They're bimetal blades with a flexible carbon steel body and high-speed steel teeth. Tooth size and number per inch are constant throughout the blade. Choose blades with more teeth per inch for a smooth finish; choose blades with fewer teeth per inch for fast, rough cutting.