Open Die Vs Closed Die Forging

The process of forging has been around since blacksmiths worked in sweltering workshops, forming the shapes they needed with strength and determination. While the process has evolved somewhat, it may not be quite as far from its origins as we like to think.

Today we are going to look at open die vs closed die forging, the differences between the two and the benefits of using these forging services in South Africa.

Open Die Forging

Open die forging is probably the closest manufacturing process to the original blacksmith work. It uses multiple dies to hammer and stamp materials until they reach the desired shape. The benefits of open die forging are:

  • Less material waste
  • Improved microstructure and fatigue resistance
  • Finer grain size
  • Continuous grain flow
  • Strength increase and improved life
  • Cost saving

Products that have been through an open die forging process can often need refining or secondary machining to create the final product. It is a process used for products required in small batches, such as shafts, sleeves and cylinders.

Closed Die Forging

Often referred to as impression die forging, closed die forging involves compressing material under high pressure to create an impression. A second forging may be required afterwards for special shapes or dimensions.

Benefits of closed die forging include:

  • Better cost for larger runs
  • No limitation on materials
  • Little to no machining is required
  • A tighter tolerance and a more precise shape can be achieved
  • The surface finish is better

The cost of this process is determined by the need to heat treat, tolerance tightness and the type of material being used.

Open Die vs Closed Die Forging

These two types are the most common forging processes, and the battle of open die vs closed die forging lives on. But the clear differences in the manufacturing process determine which is better for what you need, so luckily, there are very few nail-biting decisions that you will need to make when it comes to forging.

Please do not hesitate to contact us with any additional questions about these two options. Visit us today at or call 011 747 5700, and one of our team will assist you with any queries.