Selecting a tap is simple

Time：

2021-07-13 11:37

Cutting tap
1. Straight groove tap: used for the processing of through hole and blind hole. Iron chips exist in the tap groove, and the processed thread quality is not high. It is more often used for the processing of short chip materials, such as gray cast iron.

Straight groove tap
2. Spiral groove tap: used for blind hole processing with hole depth less than or equal to 3D, iron chips are discharged along the spiral groove, and the thread surface quality is high.

Screw tap
10~20 ° spiral angle tap can process thread depth less than or equal to 2D;
28~40 ° spiral angle tap can process thread depth less than or equal to 3D;
50 ° spiral angle tap can process thread depth less than or equal to 3.5D (special working condition 4D).
In some cases (hard materials, large pitch, etc.), in order to obtain better tooth tip strength, spiral groove tap will be used to process through hole.
3. Screw tap: usually only used for through-hole, with a length-diameter ratio of up to 3D~3.5D, iron chips discharged downward, low cutting torque, and high surface quality of the processed thread, also known as edge angle tap or tip tap.

Screw tap
During cutting, it is necessary to ensure that all cutting parts are penetrated, otherwise tooth collapse will occur.

Extrusion tap
Extrusion tap
It can be used for the processing of through holes and blind holes. It can only be used for the processing of plastic materials.
Its main features:
1. Use the plastic deformation of the workpiece to process the thread;
2. The tap has large sectional area, high strength and is not easy to break;
3. The cutting speed can be higher than the cutting tap, and the productivity can also be improved accordingly;
4. Due to the cold extrusion process, the mechanical properties of the processed thread surface are improved, the surface roughness is high, and the thread strength, wear resistance and corrosion resistance are improved;
5. Chip free processing.

Its disadvantages are:
1. It can only be used to process plastic materials;
2. High manufacturing cost.
There are two structural forms:
1. The extruding tap without oil groove is only used for the working condition of blind hole vertical addition;
2. The extrusion tap with oil groove is applicable to all working conditions, but generally the small diameter tap is not designed with oil groove due to manufacturing difficulties.