Bosch HSS Bi·Metal Hole Saw for Standard Adapter, Working Length 38 mm (16-32 mm Dia)

A bi-metal hole saw is a specialized cutting tool used primarily in construction, woodworking, plumbing, and electrical work to create clean, precise holes in various materials such as wood, metal, plastic, and drywall. It consists of a circular saw blade with teeth around the edge, attached to a metal housing. What distinguishes a bi-metal hole saw from other types of hole saws is its construction, which typically involves two different types of metal.

The term "bi-metal" refers to the combination of two types of metals used in constructing the saw. Usually, the teeth of the hole saw are made from high-speed steel (HSS), which is known for its durability and ability to maintain sharpness even under high temperatures generated during cutting. The body, or housing, of the hole saw is made from a softer, more flexible metal such as carbon steel. This combination allows the hole saw to withstand the rigors of cutting through tough materials while maintaining the sharpness of its cutting edges.

Bi-metal hole saws come in a variety of sizes ranging from small diameters suitable for electrical conduit to larger diameters used for plumbing and HVAC installations. They are often used in conjunction with a drill, either handheld or mounted on a drill press, to create holes of precise diameter and depth.

The design of a bi-metal hole saw typically includes slots or holes on the sides to facilitate the removal of debris generated during cutting, which helps prevent overheating and prolongs the life of the saw. Some models also feature pilot drills or centering bits to guide the hole saw and ensure accurate hole placement.