Open Die Forging

Open Die Forging Process

Open die forging is the process, which involves the shaping of any hot metal parts. This is done with a top die that is attached to a ram and the bottom die gets attached to a hammer or bolster. Metal parts need to have appropriate temperatures, somewhere in the range of 500°F to 2400°F. These can then be shaped into the desired configuration with the help of skilful hammering or even by applying pressure to the workpiece. Sometimes, open die forging is also referred to as free forging or impression die forging. The metal is constantly hammered and stamped to finally achieve a certain set of dimensions within the open die forging process.

Benefits of Open Die Forging

Open die forging helps in reducing the chances of voids. It is also known to help improvise fatigue resistance. With the ability to provide continued grain flow, it can also help in generating finer grain size. It provides greater strength and improved microstructure. Advanced open die forging can also produce complex shapes in addition to simpler shaped parts. Steel and related alloys are generally subjected to open die forging. A lot of other metals like copper, nickel etc. can also be shaped using open die forging.

Open Die Forging vs. Closed Die Forging

Closed die forging, also known as an impression, generally confines the metal in dies. In contrast, open die forging does not confine or restrain the metal in dies. Open die forgings are generally produced on flat dies. This process is meant for larger, simple-shaped parts like blanks, rings, bars, spindles etc. This is also considered to be the best option for custom-designed metal parts.

The biggest challenge in the open die forging process is that the workpiece has to be continuously moved as it is worked upon. It requires some complex mechanical controls and even skilled human operators at times. Closed die forging, in contrast, can be entirely automated with minimal human involvement and a much simpler process in all. However, Open die forging can result in some valuable cost savings and even limited material wastage in most cases, which is why it is highly preferred.



Q1) What is open die forging?

Dismantling a piece of metal in between more than one die which does not encircle the material ultimately is called an open die forging. With the strike of the hammer or the stamp, the content is altered and reached the required shape through repeated movements to serve the purpose of the product.

Q2) What is closed die forging?

The process in which the die moves in a direction towards each other while covering the whole or a part of the piece of metal is called closed die forging. The raw material is heated and curved in an approximate shape and size of the final finished product, and it is then placed at the bottom die.

Q3) What is the difference between open die and the impression die forging?

In simple terms, impression die forging is a process in which the piece undergoes deformation as two dies are brought together and then it gets expanded to the extent that it touches the walls of the die. But in open die forging, the material is squeezed in between both dies and then it is being deformed to reshape.

Q4) What are the different types of forging?

Forging is widely divided into three main categories which are as follows –

1) Press Forging which includes a continuous but moderate pressure to be applied in the particular area which is to be forged.

2) Hammer Forging is the most preferred method when it comes to single unit forgings.

3) Die Forging which either compresses or strikes the metal to get them turned into the designed and customized shape.

Q5) What are forging dies?

Forging Dies are tools that are made up of steel that is hardened beforehand and low-alloy, and it contains nickel, chromium and some other elements. This tool provides the mechanism to the various forging techniques which require the usage of dies.