Closed Die Forgings: Process, Common Material And Advantages

Closed Die Forgings: Process, Common Material And Advantages

Dec 14, 2021, 3:12:33 PM Life and Styles

One of the forging types for common and tiny metal components is closed die forgings, which is also called impression die forging. Closed die forging products are plastic deformation methods in which the material is pumped in a sealed shape called a die instead of the overall die developing process. Closed die forgings (also known as hot-drop forging) may generate more complicated geometries, which are incredibly close to the proportions of the completed component, as compared to open die forging. Furthermore, plastic deformation is achieved quickly using shots that push the substance to fill the die's shape. Without any intermediate re-heatings, the procedure is carried out at the plastic temperature of the metal in use.

The fabrication and design of dies, a component of the company's know-how, is essential in closed die forgings. Tool steels are the most commonly used forging dies. Due to high processing and material expenses, the price of forging dies is always much more significant, even if it is a one-time fee that will not be invoiced for subsequent batch production. Despite open die forging, which may be used to make individual components, closed die forging is often used to create series manufacturing because it is easier to absorb the expenses of the dies. 

The relative die-forged product has various advantages, such as conventional metallic flow lines along the element's surface, especially for mechanical components subjected to cyclic fatigue. This procedure also allows for lower over-dimensions, saving money on intake weights and final machining because there is less stuff to remove. Closed die forging is commonly used for essential components, such as petrochemical, railway, lifting electrical, safety systems, industrial, and farm equipment industries.

Closed Die Forging Process

Closed die forgings occur when a metal is placed in a die that looks like a mould and is connected to an anvil. Each hammer die is usually forming as well. After that, the hammer is slammed into the workpiece, forcing the metal to pour and fill the die holes. In milliseconds, the hammer strikes repeated impact. Moreover, the hammer may descend numerous times in rapid succession, based on the size and intricacy of the component.

Flashing refers to the surplus metal that is forced out of the die holes. Because the flash cools faster than the remainder of the substance and is generally more substantial than that of the steel in the die, it prevents the formation of new moments. The flash also causes the metal to keep filling the die cavity and is then removed following forging.

Go from billet form to finished shape in industrial closed die forgings, and the piece is generally pushing through a succession of cavities in a die. The initial impression is often used to disperse the metal through rough form according to the materials required later in the holes. Fullering, edging, or bending impressions are all terms used to describe this type of imprint. Following that, obstructing cavities are created, in which the component manipulates into a form that resembles the final result more closely. The workpiece frequently has generous bends and wide fillets as a result of these many phases. In a last or finisher cavity, the final form is forged. If the components are small quantities, it may be more cost-effective to skip the previous imprint cavity and process the part instead.

Common Materials In Closed Die Forgings

While nearly all metal materials apply in closed die forgings, only a percentage of the components are used in proper manufacture for the various qualities. The material involved is one of the most significant factors determining the value of forgings. Let us take a look at some of the typical materials used in closed die forgings.


Steel is perhaps the most often utilised material for closed die forgings. Carbon steel, alloy steel, and stainless steel are all used according to the forging's purpose. Stainless steel is widely used in equipment that requires oxidation and rust resistance. Because of their low cost and ease of deformation, carbon steel and alloy steel are the most often utilised materials in closed die forgings.


Aluminium is widely used because of its low density, high strength, and simplicity of machining. It is used a lot in closed die forgings, especially in the aerospace and automobile industries. Given its wide use in the automotive and aerospace sectors, it is difficult to forge locally because of its propensity for distortion after development. Thermal treatment, on the other hand, can assist in enhancing toughness and other qualities.

Brass or Copper

Closed die forgings are the most costly of the three different materials we have studied, are also routinely done with brass or copper. For pump and valve fittings, copper or brass forging has been most ordinarily utilised.

Advantages Of Closed Die Forgings

  • In contrast to investment moulding, the upfront costs of forging dies for producing metallic parts in closed die forgings are reasonably costly. Nonetheless, because of each piece's low cost, it is the most costly metal forming procedure if the elements are manufactured in high quantities.
  • The workpiece pressing between forging dies throughout the closed die forgings process refines the inner grain and improves the mechanical qualities of closed die developed components, particularly their strength. In rigging and lifting hardware, closed die forgings are the clear winner in stability and safety.
  • The tolerances of closed die forgings components are always tight because items are distorted in highly precise forging dies. Also, the surface polish is usually excellent. In most cases, we can manage closed die forgings components to within +/- 0.5mm tolerance. This forging technique is thus a netting or near-net form procedure that requires little or no modification. So, closed die forgings have a clear advantage in machining cost for the identical components created in casting and forging.
  • The material has been saved. The only material loss during the workpiece is the flash, as you will understand if you study closed die forgings. The trimming die will relocate such a moment, and you will be left with a completed forging blank. As can be seen, the flash is the sole substance that is no longer needed, although it may be recycled.

Furthermore, closed die forgings may be made from all three materials. Although closed die forging has several advantages, it cannot manufacture all metal parts; thin and complexly formed components are not viable. As a consequence, each process of metal formation has its own set of restrictions.


Steel and aluminium components are most produced via closed die forgings. As a result, closed die forgings have a wide range of applications. Forestry wear parts, mining drilling bits, construction wear parts, agricultural wear parts, lifting and rigging components, and so on might all be made using it. In a nutshell, any system that requires excellent features might use this approach.

Published by Rahul Pandey

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