A tap selection guide, teach you step by step!

As a common tool for processing internal threads, taps can be divided into spiral groove taps, edge inclination taps, straight groove taps and pipe thread taps according to their shapes. Divided into metric, American, and imperial taps. Taps are also the mainstream machining tools used in tapping. So how to choose a tap? Today I will share with you a tap selection guide to help you choose the right tap.

Cutting tap
1. Straight flute tap: used for processing through holes and blind holes. Iron chips exist in the tap groove, and the quality of the processed threads is not high. It is more commonly used in the processing of short chip materials, such as gray cast iron, etc.
2. Spiral flute tap: used for blind hole processing with hole depth less than or equal to 3D, iron filings are discharged along the spiral groove, and the thread surface quality is high. In some cases (hard materials, large pitch, etc.), in order to obtain better tooth tip strength, a helical flute tap is used to machine through holes.
3. Spiral tip tap: usually only used for through holes, iron chips are discharged downward, cutting torque is small, and the surface quality of the machined thread is high, also known as edge angle tap or tip tap. When cutting, it is necessary to ensure that all cutting parts are penetrated, otherwise tooth chipping will occur.
4. Roll tap: It can be used for the processing of through holes and blind holes, and the tooth shape is formed by plastic deformation of the material. It can only be used for processing plastic materials.

Material
1. Alloy steel: It is mostly used for hand incisor taps, which is not common at present.
2. High-speed steel: currently widely used as tap materials, such as M2 (W6Mo5Cr4V2, 6542), M3, etc., the marking code is HSS.
3. Cobalt-containing high-speed steel: Currently widely used as tap materials, such as M35, M42, etc., the marking code is HSS-E.

Coating
TIN, Nitriding treatment, TiCN, TiAlN