The teeth on these blades vary in size and pattern to reduce vibration and produce smooth cuts. The blades have a pointed tip for plunge cuts in a wide range of materials including metal, plastic, and wood. They have a 1/2" universal shank that fits most reciprocating saws. Also known as bimetal blades, these have a flexible carbon steel body with high-speed steel teeth. Choose blades with more teeth per inch for a smooth finish; choose blades with fewer teeth per inch for fast, rough cutting.