Forging can be divided into two different forms; cold forming and hot forging. Cold forming is as it sounds, a method where the material is reworked without heating while hot forging means that the material is heated and reworked in a number of different steps and possibly with subsequent calibration.
The simplest type of forging is called hammer forging or die forging, which means that the material is transformed without a forging die and that the component is formed with several hammer blows. The method and tools used are relatively inexpensive, but more refinement is required because the method gives an imprecise result. Hammer forging is mainly used for low volumes or large components.
When forged, the component is produced in a forging die in a hydraulic or mechanical press in one or more steps. The tooling cost is higher than for hammer forging but the forgings have a more precise shape and productivity is higher.
Some components can be made in an automatic forging press. In principle, these presses are built up as for the cold forming of fasteners, with the difference that you heat the rod here. This technology has high productivity at a production rate of up to 160 components per minute and requires larger series (a rule of thumb is at least 50,000 units per year) to provide cost-effectiveness, due to high tooling costs and long rig times.
Precision forging is a forging technique where ready-made functional areas can be forged. Cold calibration is often used to get the right tolerances.
