Making shapes of metal, of the formation of parts and components, can be accomplished by at least three different methods. These four include hot forging, cold forming, and machining.
Machining is the one option that creates the most waste and often is the most expensive and time-consuming. With machining, a solid workpiece is shaped, typically with CNC (computer numerical control) software to remove part of the solid form to create the shape. While highly precise, this method is not always the best option for all parts and all alloys and metals.
Hot forging can include extrusions or working with metal that is heated to the point where it can be easily worked. This involves more energy expenditure than cold forming, plus it also requires additional time and equipment. Hot forging also can change the internal structure and physical properties of specific alloys, which needs to be carefully considered.
Cold Forming
Cold formed parts are made in a similar process to hot forging and extrusion, just without the need to heat the metal or alloy. Without the need for heating, this is a faster and less costly method and offers a waste-free option for creating simple to complex shapes for all types of applications.
The benefit to choosing cold formed parts is that the system is fully automated and can produce high volumes of parts in a short period of time, keeping production costs down.
As with hot forging through extrusion, the cold metal is forced through a die by using high-pressure rams. There are limitations as to the size of the component that can be formed based on the resistance of the metal or the alloy to the process.
With cold formed parts, there is no change in the physical and internal properties of the metal. This means that parts don’t have to be stress relieved or further treated after fabrication, which is another important factor to consider for small or large volume production.
