Mechanica Technical Solutions
Home | Contact | About
Manufacturing Processes > Forming Processes > Swaging




Process description

Process of gradually shaping and reducing the cross section of tubes, rods and wire using successive blows from hard dies rotating around the material (on a mandrel if necessary for tubular sections). Operation performed at ambient temperature.


Carbon, low alloy and stainless steels, aluminum, magnesium, nickel and their alloys. Copper, zinc, lead and their alloys less commonly.


Process variations

  • Using a shaped mandrel can generate inner section profiles different to outer.
  • Hand forging: hot material reduced, upset and shaped using hand tools and an anvil, commonly associated with the blacksmith’s trade. For decorative and architectural work.

Economic considerations

  • Production rates moderate to high (100–300/h).
  • Lead time typically days depending on complexity of tool.
  • Special tooling not necessarily required for each job.
  • Material utilization excellent. No scrap generated.
  • Some automation possible.
  • Economical for low production runs. Can be used for one-offs.
  • Tooling costs high.
  • Equipment costs generally moderate.
  • Direct labor costs low to moderate.

Typical applications

  • Used to close tubes, produce tapering, clamping and steps in sections
  • Many section types possible either parallel or tapered
  • Tool shafts
  • Punches
  • Chisels
  • Handles
  • Exhaust pipes
  • Cable assemblies
  • Architectural work

Design aspects

  • Complexity fairly high. Round, square, rectangular and polygon sections possible either parallel or tapered. Splines and contoured surfaces also possible.
  • Holes possible, but only through the length of the part.
  • No undercuts or inserts possible.
  • Draft angles ranging 0–3.5°.
  • Minimum section =2.5 mm.
  • Maximum section =50 mm.
  • Minimum solid diameter =Ø2.5 mm.
  • Maximum solid diameter =Ø150 mm.
  • Maximum tube diameter =Ø350 mm.
  • Minimum length =1.5 mm.
  • Maximum length =250 mm.

Quality issues

  • Cold working of material gives good mechanical properties and compressive surface stresses improve fatigue life. Surface finish of stock material is markedly improved.
  • Surface detail is good to excellent.
  • Surface roughness values ranging 0.8–3.2 µm Ra.
  • A process capability chart showing the achievable dimensional tolerances for swaging is provided.