Die Forging

An Overview Of Closed Die Forging

Closed die forging, also known as impression-die forging, is used to make small or medium-sized metal components. It is a plastic deformation method in which the materials are forced to flow inside a sealed shape called a die instead of open die forging.

Near die forging (also known as hot-drop forging) may generate more complicated geometries that are incredibly close to the end component’s dimensions than open die forging.

Plastic deformation are applied quickly by a series of shots, forcing the materials to cover the shape of the die. Without any intermediate re-heating, the procedure is carried out towards the thermoplastic temperature of the materials in use.

The design and fabrication of dies, part of a manufacturer’s know-how, is a vital stage in closed die forging. Tool steels are the most often used materials for forging dies. The cost for forging dies is usually substantially higher due to the expensive material and machining costs.

However, it is a one-time expense client would not charge for future batch production. Closed die forging, as opposed to open die forging, is used to create serial manufacturing because it is simple to absorb the expenses of the dies. The related die-forged product has various benefits, such as the material’s usual flow lines and the product’s profile, especially on mechanical components subjected to cyclic fatigue.

Because there is less material to remove, this procedure allows for lower over-dimensions, which reduces weights & final machining costs. Closed die forging is often used for essential components, such as those found in the railway, petrochemical, electric, lifting & safety system, industrial, and agricultural equipment industries.

The Closed Die Forging Process

Closed forging forms a metal in a die that resembles a mould and is linked to an anvil. The hammer die is usually formed as well. The hammer is subsequently dropped on the workpiece, forcing the metal to flow & fill the die cavities. Within milliseconds, the hammer makes many contacts. Based on the scale & intricacy of the item, it may drop the hammer numerous times in rapid succession.

Flashing refers to the surplus metal forced outside the die cavities. The flash cools faster than the other materials, and the flash is generally more durable than the metal inside the die, and it helps prevent new flash from developing. The flash also causes the metal to cover the die hole, and after forging, all-flash is eliminated.

Common Materials Used In Closed Die Forging

While practically every metal material is employed in closed die forging, only a fraction of the materials are used for the various defective manufacturing features. The material used is one of the most significant factors impacting the value of forgings. Let’s look at some of the most common materials used in closed die forgings.


Steel is the most frequent material used in closed die forging. Based on the forging utilised, alloy steel, carbon fibre, & stainless steel all are used. Stainless steel is widely used for corrosion- and rust-resistant components. Due to their low cost and ease of deformation, alloy & carbon steel are most often used in closed die solidification.


Aluminum is frequently employed because of its low density, great strength, and simplicity of machining. It is often used in closed die forging, particularly in the automotive & aerospace sectors. Although it is widely used inside the aerospace & automotive sectors, it presents a problem for domestic forging due to its ease of deformation.

On the other hand, heat treatment may enhance the hardness and other qualities.

Copper or Brass

The most costly of these three materials listed, copper or brass, is also widely used during closed die forging. For valve & pump fittings, copper forging and brass forging is often utilised.

Benefits of Closed Die Forging

In contrast to investment casting, the upfront expenditures of forging dies for creating metal parts in closed die forging are pretty significant. Nonetheless, if the components is produced in large quantities, it is the often valued metal forming technology due to the cheap cost of every piece.

Pressing the material between forging dies during closed die forging operation refines the inner grain. The mechanical qualities, particularly the strength, of the closed die produced will enhance components. So, closed die forging is a one-of-a-kind option for safety and power, such as lifting and rigging gear.

Because goods are deformed in highly precise forging dies, the tolerance for closed die forging components is always tight. And the surface polish is usually excellent. You can normally generally regulate closed die forging products with +/- 0.5mm tolerance. As a result, this forging technique is a net or near-net form procedure that needs little or no machining.

As a result, closed die forging and castings can have clear benefits for identical components created in developing & castings due to lower machining costs.

The material has been preserved. If you study closed die forging, users will discover that the only material wastes generated throughout the forging process are flash. Trimming the die will cause such a flash, you will be left with a completed forging blank. As a result, you can see that the only excess material is flash, which you may recycle.


Closed die forging materials is not restricted. Steel, aluminium, brass, and other metals may can used. Although closed forging has several advantages, it cannot produce all metal components. It is not possible for delicate and complicated shaped parts. As a result, each metal forming method has restrictions.


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