Types and applications of tap for precision parts processing

The tap is one of the standard tools for machining cylindrical and conical internal threads of precision parts. Its structure is simple and easy to use, so it is widely used. The basic outline of the tap is a screw with a groove in the longitudinal direction to form a cutting edge and Chip slot.

There are many types of taps, which can be divided into the following types according to different uses and structures:

1. Hand taps: Hand taps are commonly used in single-piece or small batch production. Its tail is a square head round handle. Hand taps are generally made of two or three sets, which are processed in sequence for processing internal threads. .

2. Machine taps: Machine taps have the same shape as hand taps, but the tooth shape needs to be shoveled. Due to the high power of the machine tool and good guidance, the single tap is commonly used to tap threads, but when the processing diameter is large, the material hardness or toughness is relatively high For large workpieces, two or three sets of tapping threads are also used.

3. Nut taps: Nut taps are divided into three types: short shank, long shank and curved shank. They are all made into single cones, which are specially used to process nuts. Nut taps can be used on ordinary machine tools and automatic machine tools with high productivity.

4. Content chip taps: The core part of the content tap has chip holes, and there are a number of non-through slots in the cutting taper to improve the cutting performance and chip removal performance. It is suitable for processing large diameter and high-precision holes in precision parts.

5. Taper thread tap: The taper thread tap has good sealing performance and can compensate the diameter error by axial displacement, so it is widely used in pipe joint processing. There are two types of tooth angles, 55° and 60°. When the cutting force is large, and the torque increases with the depth of the tap cutting into the workpiece, it is generally used for maneuvering. In order to prevent the torque from breaking the tap too much, a safety device is often used during cutting.

6. Extruded taps: Extruded taps are those without chip slots. They use the principle of plastic deformation to process threads. Their main features are high precision machining of thread precision parts, small surface roughness values, long tap life and high strength , High-speed tapping, high productivity, but difficult to manufacture, suitable for processing various plastic materials.

7. Pull-out tap: The working part of the pull-out tap is a spiral groove tap with high productivity, easy operation and stable dimensional accuracy of the workpiece. The surface roughness value can reach Ra1.6~0.8μm. It can process trapezoidal, rectangular single and multi-line internal thread.