Our processes

Rotary swaging , axial forming , bending, end forming and autofrettage: Discover the versatile methods applied by Felss. We combine innovative technology with the best idea and thus create tangible benefits for users.

Rotary swaging

Hollow lightweight shafts due to intelligent material distribution

  • Internal and external profiles in highest precision
  • Highest degrees of deformation in cold condition
  • Strength increase due to uninterrupted grain structure and work hardening
  • Ressource efficient, no chips due to forming instead of machining
  • Highest productivity and output due to short cycle

Axial forming

High precision internal andexternal splines by cold forming

Felss patented recursive axial forming for: 

  • Internal splines especially in blind holes
  • Very thin-walled components
  • Highest accuracy up to tolerance DIN class 5
  • Nearly perfect pitch and profile variation due to forming all teeth together by a one-piece tool
  • Involute profiles, serrations and other profiles like ball shapes
  • High output of up to five parts per minute


Highest bending quality and repeatability

  • Complex geometries bendable line with short straight between the arches 
  • Rolling, draw bending , push roll- or collet bending, and bending both sides as well as the use of multiple bending levels in a tool possible
  • Design freedom and flexibility in shape
  • Great variety of different tube diameters in a tool
  • Integration into existing processes and expandability
  • Highest bending quality with maximum enclosure in the bending tool
  • Special tool geometry minimizes pipe incidence and terminal prints
  • Bending without mandrel   


Maximum pressure for extreme stability

After the autofrettage the tubes are much more resistant. Autofrettage is to increase the life at using operating pressures from 1,500 to more than 2,000 bar. By applying a single very high internal pressure (up to 12,000 bar) by controlled plasticization and residual stress build the fatigue strength is significantly improved. The process is very flexible and can be integrated into existing production systems Autofrettage is the only way for curved pipes for drilling branches, cross section changes and complex geometries to be made stronger.

Fatigue strength that can not be achieved even with higher material quality or higher wall thicknesses can be achieved.

End forming

Perfect surfaces and maximum dimensional accuracy

  • high accuracy     
  • Very high surface quality in the sealing area     
  • No " spangle " through joints in the tool     
  • Free of coating     
  • 100 % controlled