Cold forging and hot forging represent two different approaches to achieving the same result: deforming a metal material to produce a desired shape. As you might guess from the terms, hot forging relies on the application of heat to produce the metal deformation, while cold forging does not. A key difference between the two processes is that, with hot forging, the deformation occurs above the metal’s recrystallization point, while with cold forging, it takes place below the recrystallization point.
What Is Hot Forging?
The hot forging process involves the application of extreme heat, with the desired temperature depending on the type of metal. For instance, the average temperature required for deforming steel is approximately 2,100 degrees Fahrenheit; for aluminum alloys, the temperature range is 680 to 970 degrees Fahrenheit; for copper alloys, the range is 1,300 to 1,470 degrees Fahrenheit. The high temperature is necessary to prevent strain hardening during deformation.
Hot forging is typically the best choice for metal parts used in technical applications and for deforming metal that has a high formability ratio. Key advantages of hot forging include a homogenized grain structure, low work hardening, increased ductility and a reduction in chemical inconsistencies. On the downside, hot forging offers less precise tolerances, the potential for warping during cooling and the possibility of an adverse reaction between the metal and the surrounding environment.
What Is Cold Forging?
The term cold forging is a bit of a misnomer: The process actually takes place at or near room temperature. Cold forging also involves just slightly heating up the metals to make them more malleable. However, extreme heat is not applied so that the metal is still being formed below the recrystallization point. Also known as cold forming or cold head machining, cold forging uses sophisticated machinery to produce a precise combination of high speed and extreme pressure to shape the metal into the desired components.
Perhaps the biggest advantage of cold forging is its lower cost. Cold-formed parts require less finishing work, resulting in fewer fabrication steps. Other benefits include less potential for parts contamination during forging, greater dimensional control, greater ability to handle high stress and high die loads and the ability to produce near-net shape parts. Cold forging disadvantages include a finished product that is less ductile, the potential for residual-part stress, and the need for stronger tools and heavier, more powerful equipment.
STS Intelli Offers Reliable, Cost-Effective Cold Forming Services
If cold forming makes better sense in your manufacturing environment, STS Intelli offers an assortment of cold-forming services that can meet your unique job requirements. As one of the leading micro-cold forming companies in the United States, we can provide a reliable, cost-effective solution when working with all types of materials, including precious metals and various metal alloys. We have perfected various cold-forming techniques including forward, backward and combined extrusion, as well as upsetting. We can also recommend the best method for your applications and budget.
Contact STS Intelli to learn more about the benefits of cold forging vs. hot forging and to receive a no-obligation cold forging quote today.