Forming taps – for more strength
Both taps and forming taps are used to produce internal threads. In contrast to taps, forming taps or have no cutting edges or flute - at most narrow oil grooves. They work with forming edges and polygonal profiles. Since thread forming leads to compression and deformation of the fiber course, this results in col work hardening. The result is increased material strength of the formed thread.
Especially if you do not want chips, such as in blind holes, the forming tap is the first choice. According to the material to be machined, the surface of the tool can be coated.
Suitable materials for cold forming
The formin tap is used to produce internal threads by cold forming without producing chips. It requires that the material is suitable for this. For this purpose, it must have good flow properties and a minimum elongation at break of eight percent. These requirements are met by light metals, pure and precious metals, soft steels, long-chipping non-ferrous metals and soft bronze, zinc and die-cast alloys.
Brittle, short-chipping materials with minimal elongation - such as gray cast iron - cannot be cold formed. This also applies to high-strength steels above 1200 N/mm² or AISI alloys with more than 12 percent Si content. Here, cold forming is only possible with coated carbide thread formers. The maximum thread pitch is 4 mm and the maximum outer diameter is 60 mm.
Advantages on one view
- Higher cutting speed
- Improved tool life time
- No chip accumulation: no chip jamming, no chip disposal
- Higher material strength
- Better surface finish
- No pitch errors
- No unacceptable pre-widening
- No over/undercutting
In most cases, thread production is at the end of the process chain. This makes the quality and reliability of the threading tools more important. Our experienced application engineers will be happy to advise you on the optimum technical and economic solution for thread production.