Steel Forgings- Hot Forging vs. Cold Forging

Forging is one of the most popular processes for manufacturing metal components. The process involves applying compressive forces to shape the workpieces. Depending on the forging temperature, the process is classified into hot forging and cold forging.

What is Hot Forging?
Hot forging is done at extremely high temperature, like up to 700-900 degrees Celsius for Cu-alloys, 300-550 degree Celsius for Al-alloys and 1000-1200 degree Celsius for steel. Such high temperatures are necessary to avoid the problem of strain hardening during metal deformation.
Benefits of Hot forging
Hot forging significantly increases the ductility of the forged components and makes them ideal for a host of configurations. As compared to cold forging, hot forging is also more flexible as it allows the creation of custom components. The surface quality offered by hot forging enables many different finishing works, like coating, painting, or polishing as per your custom needs.
Drawbacks of Hot Forging
One possible drawback of hot forging is lower dimensional tolerance as compared to cold forging. After a component is forged, the cooling process too requires specific conditions to prevent the problem of warping. Varying grain structures and the possibility of a reaction between the workpiece and atmosphere are two other drawbacks.  
What is Cold Forging?
Room temperature is adequate for cold forging. Two dies are used to squeeze the workpieces until they take the desired shape. Other processes like drawling, rolling, spinning, pressing, heating and extruding are used after cold forging to create the final product.
Benefits of Cold Forging
Manufacturers typically prefer cold forging as the alloy steel forgings that are cold forged usually require minimum finishing work which helps in reducing the manufacturing costs. Moreover, as precision shapes can be manufactured with cold forging also reduces wastage of materials. Longer die life and higher production rate also make cold forging a better option over hot forging.
Drawbacks of Cold Forging
As per your requirements, some characteristics of cold forging might result in significant drawbacks. For instance, the process can only be used for shaping simple components in very high volumes. Thus, if you are looking for a custom component, cold forging might not be the right option.
Another major drawback of cold forging is the lower ductility of forged components due to which they are not suitable for several configurations. Residual stress might also occur due to the grain structure which is responsible for giving strength to the materials.