Difference Between Casting and Forging

Main Difference – Casting vs Forging

Both casting and forging are metal-working processes commonly used in industry. They are often not restricted to metals. The two processes differ in their principal operation. During the process of casting, the metal is heated until it melts and then the molten liquid is poured into a mould to obtain the desired shape. In the case of forging, the metal is being treated while it is in its solid state using the compressive forces until the desired shape is obtained. This is the main difference between casting and forging.

What is Casting

As mentioned in the introduction, this is a process where the material involved is first heated until it melts. Therefore, there are no restrictions on the shape or the size of material that is to be used for the process of casting. As all material will be melted at the start, it makes no difference. Next, the molten material, which is in liquid form, is poured into a mould with a cavity to obtain the required shape. It is then left to cool down. Once the material is cooled, the solid can be removed out of the mould. It can either be ejected or broken free. This solid material which has been newly shaped is called the ‘casting’.

The process of casting is mainly performed on metals and other cold-setting material. These are the types of polymer material that cure together, forming cross-links in order to produce hardened material. Casting helps in setting these mixtures into solid shapes. Casting can be perfected to higher quality producing material with greater strength and wearability depending on the correct selection of alloys, and heating them to their optimum temperatures.

What is Forging

Forging, in contrast to casting, is a method of producing differently shaped material while they are still in their solid state. This process does not involve heating till they melt and pouring into moulds for setting. The shaping of the material is done by the use of localized compressive forces. In order to deliver these forces, either industrial scale hammers or dies are used. A die is a tool which is used to cut and shape a material with the aid of the press technology. Forging is performed under various temperatures; cold, warm and hot, depending on the material in question. The process of forging is preferred where a component requires higher strength. Also, it assures uniformity of composition when compared to casting. Forged material has a firm grain structure which makes them stronger in order to handle impact better than cast material. This firm structure also excludes cavities and porosity from the composition.

The process of forging dates back to the 12^th century where it was thought to be performed by smiths for various metal works. It has turned into a worldwide industry today since the industrial revolution. Kitchenware, hardware tools, weapons, jewellery are made by this method.

Difference Between Casting and Forging

Definition

Casting is a metal-working process where the metal is first heated till it melts, then poured into a mould and made to cool to obtain the shape.

Forging involves the use of localized compressive forces on the solid material in order to create desired shapes.

Strength of the Product

Casted material is low in strength as they are poured into a cavity which lets the material take its shape freely.

Forged material are stronger as they possess a definite grain structure which is pressed with force, increasing their mechanical strength.

Suitability for Hollow Shapes

Casting is often preferred for the production of material containing hollows spaces or cavities.

Forging excludes cavities and porosity from their compositions.

Uniformity

The casted material is not always uniform.

Forged material can be made to a uniform structure preserving consistency in shape.

Size Restrictions

Casting doesn’t have any size or shape limitations as all material will be melted before putting them into shape.

Materials weighing up to 50kgs can be forged yet higher power is required if material to be forged is heavier than 50kgs. In this case, casting would be the alternative.