The Differences Between Closed & Open Die Forging

When it comes to deforming metal, there are numerous options using the concept of forging. Two of them include open and closed-die forging. While both utilize the same basic process, they differ when it comes to the use of dies. Let’s go through the definitions and differences, and the various pros and cons of each.

What Is Open Vs. Open and Closed Die ForgingClosed-Die Forging

Open-die forging, also known as free forging or smith forging, is the process of striking a hammer and deforming a workpiece, which is placed on a stationary anvil.

The piece of metal is deformed between “dies,” which are usually flat and don’t enclose the metal completely. The dies hammer or press the metal through a series of movements in order to alter the dimensions until the desired shape is achieved.


  • Little or no tooling cost
  • Reduced lead time


  • Not suitable for forming precision parts or other close-tolerance applications
  • Machining is often required to achieve accuracy and desired features

Closed-Die Forging

Closed-die forging, or impression-die forging, involves the metal being placed in a die that contains the shape of the part. The metal is then hammered or pressed, causing the metal to flow and fill the die cavities and the shape of the part. After forging, the flash is removed.

With closed-die forging, little to no machining is needed. The process utilizes the force from the hammer or press and, often, heat in order to deform the metal to fill an enclosed die impression that contains the shape of the part.


  • Better surface finish
  • Little or reduced machining
  • Cost effective for large production runs
  • Dimensions of tighter tolerances and net shapes can be achieved


  • Not economical for short production runs due to the high cost of die production
  • Higher setup cost due to costly machines and furnaces

If you think your production needs may call for closed-die forging, we can help. At Canton Drop Forge, our wide range of capabilities and more than 100 years of experience makes us uniquely qualified and prepared for future opportunities in markets all over the world. To see how Canton Drop Forge can provide precise custom forging solutions for your industry’s needs today, contact our forging experts.


  • This field is for validation purposes and should be left unchanged.