Bosch Jig Saw Blades are designed to cut materials quickly, smoothly and precisely. These blades are ideal for medium to thin metals 1/4 In. to 1/8 In. thick (ferrous and non-ferrous). They have 21 TPI with unique tooth geometry including rigid and aggressive profiles – plus ackward taper design – for speed in metal cutting.The blades are made with quality Bi-Metal and high-carbon steel, providing precise, clean cuts. They have optimal tooth spacing, shape and cutting angle. This provides cutting speed, cleanliness of cut and durable performance. The blades have a T-shank design for maximum grip and stability; it is the industry standard and fits most professional and consumer brand jig saw makes and models, and the blades provide the best fit and long life.