Cold forging: procedures, properties and advantages

Cold forging: procedures, properties and advantages Throughout history, cold forging has aroused growing interest, becoming the most suitable production process for the production of different types of parts. The most frequently cold-forged components are small metal parts and bolts. These are mostly elements used in different sectors: automotive, aerospace, oil & gas, hydraulic and, with a growing trend, also electrical.

Cold forging is suitable for both ferrous and non- ferrous metals.

Cold forging: procedure

In cold forging, a length of wire rod is cut at room temperature and, in a succession of several dies, is plastically deformed at high speed, through considerable pressure.

The deformations obtainable through the dies are extrusion, pressing, heading, drawing and lamination. Cold forging is a very complex process, which requires a large amount of force, as the dislocations in the metal crystalline structure due to it generate a rapid hardening of the material.

This procedure provide that material is brought beyond the point of elastic resistance, assuming the shape of the matrix, but never beyond the yield point, in order to avoid cracks.

The hardening makes the grain structure stronger and a subsequent heat treatment is not necessary. The increase in the mechanical characteristics of the components made by cold forging is sometimes so remarkable that it exceeds those of an analogue hot forged, then machined.

Furthermore, with proper lubrication, the life of cold forging dies increases significantly compared to hot forging ones.

Cold forging: properties

  • High production speed
  • Automated process
  • Repetitiveness of the process
  • Constancy of quality
  • High dimensional accuracy
  • High surface quality
  • Saving of raw materials, “zero waste”
  • Improvement of mechanical characteristics
  • Weight/strength ratio optimization
  • Often unnecessary heat treatment
  • Often unnecessary subsequent machining

Why cold forging?

We can therefore state that, in the case of large series, cold forging, among all the plastic deformation production processes, guarantees the best value for money.