Metal Casting: Metal Casting Processes, Types, Advantages

By Mohit Uniyal|Updated : August 3rd, 2022

The earliest Metal Casting that has been discovered is a copper frog, which is thought to have been created in Mesopotamia about 3200 BCE when copper was a widely used material. Later, iron was found, perhaps about 2000 BCE. However, the first cast iron manufacturing did not start until about 700 BCE in China. Interestingly, around 645 BCE, China also developed the sand molding technique for metal casting.

Since ancient times, casting techniques have been frequently utilised to create sculpture (particularly in bronze), jewellery made of precious metals, tools, and weaponry. 90 per cent of durable items, such as automobiles, trucks, trains, aeroplanes, mining and construction equipment, and more, are made of highly developed castings. The technique of metal casting of useful items has evolved over thousands of years to become more precise and mechanised, yet the procedure has largely not changed at its foundation.

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What is Metal Casting?

Metal casting is most frequently used to create intricate forms that would be challenging or expensive to create using alternative techniques. Many of the metal items we use daily are made using it, including school bus pedals, railway wheels, automobile parts, and more.

Metal Casting Definition

Metal casting is “ A manufacturing process in which metal is poured into a mould cavity, cooled, and then shaped into the desired shape before being removed from the mould, is called as the metal casting process." The oldest and most important industrial process in history is probably metal casting.

Additionally, metal recycling serves as a cost-effective supply of raw materials for metal casting foundries, thereby lowering the amount of discarded metal that may otherwise wind up in landfills.

Metal Casting Process

When compared to machining an item out of solid metal, metal casting is frequently a less expensive way to make a piece. But the metal casting process is a little time-consuming. The various steps involved in the process of making a product through metal casting are listed below:

  1. Patternmaking: The replica of the casting's exterior is known as a pattern. Wood, metal, plastic, or plaster are common materials for patterns. Patternmaking is critical in industrial part-making because accurate calculations are required to make components fit and operate together.
  2. Core making: An extra piece of sand or metal is used to mould the internal form for a hollow casting. This piece is called the "core."Cores are generally sturdy yet collapsible, allowing for easy removal from the completed metal casting.
  3. Molding: Melted metal is poured into the mould cavity and allowed to harden. After the casting has formed, the shakeout process occurs, in which the moulds are vibrated to remove sand from the casting. Typically, removed sand is collected, cooled, and recycled for use in subsequent castings. Sand Casting Conditioner enhances the process of separating sand from castings by removing and chilling sand and castings and evaporating moisture. The end product is a clean cast.
  4. Cleaning: The cast metal piece is taken from the mould and fettled in this final stage. The object is cleansed of any moulding material, and rough edges are eliminated during the fettling.

Advantages of Metal Casting

As with any other manufacturing process, a basic understanding of the process and its benefits and cons is required for generating low-cost quality engineer products. Some advantages of the metal casting process are listed below.

  • Internal cavities and hollow portions are simple to cast in metal casting.
  • Casting can be used to cast materials that are challenging or expensive to produce using other production methods.
  • Complex shapes can be created through metal casting.
  • The majority of metals can be cast.
  • Casting is less expensive for medium to large quantities than alternative manufacturing techniques.
  • One-piece casts allow for the production of substantial components.
Important Topics for Gate Exam
Internal and External ForcesLami's theorem
PsychrometryComposite Material
Types of PatternsGear Design
CeramicsSystem of Forces
Principle of Virtual WorkAdmixtures
Sand CastingHeat Treatment Process


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FAQs on Metal Casting

  • The method of producing items by pouring molten metal into an empty-shaped area is known as metal casting. This method is really helpful in creating the hollow portions and internal cavities of the equipment in bulk.

  • Metal casting is classified into two types: metal casting with reusable molds and metal casting with expendable molds. Slush casting, centrifugal casting, pressure casting, and die casting comes under metal casting with reusable molds while investment casting and sand casting shell molding come under metal casting with expendable molds.

  • Fettling is the removal of surplus material from castings that are frequently created by the separating lines of the die during the casting process when molten material is fed into the die/mold. Fettling involves the conversion of a raw casting into a workable component.  The item can then be heat-treated to meet the needs of the final application.

  • An additional piece of sand or metal is used to mould the inside contour; the passage of a hollow casting is called a core. Cores are put into a mould cavity to make the inside surfaces of castings. Cores are often strong but collapsible, allowing them to be easily removed from the finished metal casting.

  • Metal casting requires extremely affordable tools and may be used to produce quite complicated forms in a very simple manner. Metal casting production may employ a wide range of materials. It is the only technique to construct the component when the object's size is huge.

  • The sand moulding casting process is a more laborious and time-consuming process. The final product of the metal casting process does not have a good quality surface finish. Most of the time, casting products have non-uniform mechanical properties due to non-uniform cooling.



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