What function does a tap serve in metalworking or woodworking?

In metalworking and woodworking, a tap is a tool specifically designed to create internal threads in a pre-drilled hole. This threading allows for the insertion of screws or bolts that can securely join two pieces of material together, making the tap essential for tasks that require precise threaded connections.

When a tap is turned into the material, it cuts into the surface, forming spiral grooves that are the reverse of the external threads found on screws. This process is crucial when a durable and reliable fastening method is needed, as internal threads created by taps provide a strong grip for fasteners, allowing for efficient assembly and disassembly of components.

While joining pieces, enlarging holes, or marking lines are also important tasks in woodworking and metalworking, they do not directly describe the specific function of a tap, which is solely focused on the creation of internal threads.