A jigsaw, sometimes referred to as a sabre saw, is a versatile handheld power tool used for making either straight or curved cuts on a variety of materials, including wood, plastic, ceramic or metal. A handy feature of the jigsaw is its ability to use a number of different types of interchangeable blades. The type of material cut, along with the finish required of the cut, typically determines the type of blade used.
Shank - Two primary types of jigsaw blade shanks are used, according to Inside Woodworking. T shank blades feature a T-shaped shank that is typically held in place by a vertical screw mechanism. U-shank blades feature a U-shaped cutout at the base of the shank which permits the blade to remain in place with a horizontal screw mechanism. The jigsaw manufacturer dictates the type of blade shank that the jigsaw model can accommodate. Some jigsaws will accommodate both types of blade shanks, but it is always best to check first before making a purchase.
Materials - Three basic types of materials are used for jigsaw blades. The type of material cut typically dictates the type of material the blade is made from. High-speed steel blades are usually the best choice for cutting all types of wood products. Cobalt steel blades hold up better when cutting metal products. Carbide grit blades are designed for working with such materials as ceramic tile, marble, masonry board and some types of concrete.
Teeth Per Inch - Jigsaw blades are frequently rated in teeth per inch. A general rule is that blades with a lower number of teeth per inch are better for quick, rough cuts on soft materials. Blades with a higher number of teeth per inch are designed for harder materials. Blades with a higher number of teeth per inch make a finer cut but also cut more slowly than blades with fewer teeth per inch.