For processing ordinary internal threads on nuts or other machine parts (ie tapping). Machine taps usually refer to high-speed steel grinding taps, suitable for tapping on machine tools; hand taps refer to carbon tool steel or alloy tools Steel rolling (or incisor) taps are suitable for manual tapping.

The tap is a tool for processing various medium and small size internal threads. It has a simple structure and is easy to use. It can be operated manually or on a machine tool. It is widely used in production.

For small-sized internal threads, taps are almost the only machining tool. The types of taps are: hand taps, machine taps, nut taps, extrusion taps, etc.

Tapping is a relatively difficult machining process, because the tap is almost buried in the workpiece for cutting, and its processing load per tooth is greater than other tools, and the contact surface of the tap with the workpiece along the thread is very large. When cutting the thread It must contain and exclude chips, so it can be said that the tap works under very harsh conditions. In order to make tapping go smoothly, various problems that may arise should be considered in advance. Such as the properties of the workpiece material, what tool and machine tool to choose, how high the cutting speed to choose, and the amount of feed.