Top 6 Casting Techniques Used in Metal Working Today

When it comes to metal working, the challenge isn’t just about shaping metals – the real challenge is shaping them right. Engineers, procurement heads, and product designers often grapple with choosing the casting technique for their needs. 

One wrong move can lead to expensive tooling, flawed parts, or missed deadlines. Whether you’re producing a precision turbine blade or a rugged pump housing, the success of your project hinges on choosing the most suitable casting method. 

And with so many options out there, each promising accuracy, durability, or cost-efficiency, how do you really know what works best for your application?This blog unpacks the top 6 casting techniques used in metal working today. We’ll walk you through how each method works, its pros and cons, and where it fits into real-world manufacturing.

What Is Casting?

In the world of metal working, casting is the foundation of shaping metal into functional parts. Casting refers to the process of pouring molten metal into a mould to create a desired shape, followed by cooling and solidification. Whether it’s a massive machinery part or a precision automotive component, casting plays a pivotal role across industries such as defence, aerospace, construction, marine, and agriculture.

Casting is no longer just about melting and pouring. Today, foundries and stainless steel casting manufacturers in India rely on multiple advanced casting techniques, each designed to suit different performance needs, geometries, tolerances, and cost parameters.

With technological advancements reshaping manufacturing, knowing the right casting technique is essential for achieving design efficiency, material integrity, and cost-effectiveness.

1. Green Sand Casting

A time-tested and widely used method, green sand casting derives its name not from its colour, but from the moisture in the mould mixture. This mixture typically contains silica sand, bentonite clay, water, and a few additives. When packed around a pattern, it forms a mould cavity into which molten metal is poured. 

Metal working products manufactured with green sanding casting process find their applications in: pump housings, motor components, flywheels, marine anchors, and outdoor architectural castings. Many Steel foundry prefer green sand for its simplicity and scalability.

How it Works:

• The pattern is pressed into the sand to create the mould cavity.

• Molten metal is poured and left to cool.

• After solidification, the mould is broken to retrieve the casting.

Advantages:

• Highly economical for low to medium batch production.

• Compatible with almost all ferrous and non-ferrous alloys.

• The sand can be reclaimed and reused, reducing material costs.

2. Furan Resin Sand Casting

A step-up from traditional sand casting, this method uses furan resin (a thermosetting binder) instead of clay to bond the sand. The result? A chemically hardened mould that offers significantly improved strength and detail reproduction. 

Products manufactured from this process are used in agricultural parts, engine blocks, lamp post bases, marine components, and heavy-duty machinery parts. It’s frequently chosen by stainless steel casting manufacturers in India when casting weight and surface detail are priorities.

Process Overview:

• Silica sand is mixed with furan resin and a hardener.

• The mix is packed around the pattern and allowed to cure.

• The mould is then removed, and molten metal is poured in.

Advantages:

• Excellent surface finish and dimensional accuracy.

• Ideal for large, complex castings.

• Reduces common casting defects like blowholes or shrinkage cavities.

3. Lost Foam Casting

This modern evaporative pattern process replaces traditional patterns with polystyrene foam, which vaporizes upon contact with molten metal, leaving behind the desired cavity. Products are best used for: Cylinder heads, crankcases, turbine blades, and artistic castings. In applications where form and detail are non-negotiable, lost foam offers unmatched flexibility in metal working.

Steps Involved:

• A foam pattern replicates the final casting shape.

• It is coated with refractory paint and placed in a flask filled with unbonded sand.

• Molten metal is poured, vaporising the foam and taking its shape.

Strengths:

• Seamless surface finish with no parting lines.

• Supports intricate geometries and hollow sections without complex cores.

• Lower overall tooling cost in mass production.

4. Investment Casting

Also known as lost wax casting, this method creates high-precision parts by encasing wax patterns in a ceramic shell. Once the shell hardens, the wax is melted out, and the mould is filled with molten metal.

Applications of investment casting can be found in aerospace brackets, medical implants, gears, and impellers. Investment casting is the preferred method among stainless steel casting manufacturers in India, where precision engineering is key.

Process Flow:

• Wax patterns are formed and assembled onto a central tree.

• Layers of ceramic slurry are applied to form a shell.

• The wax is melted and drained, and the shell is fired.

• Molten metal is poured, cooled, and the shell is broken away.

Advantages:

• Exceptional accuracy and detail replication.

• Suitable for thin-walled or complex components.

• Reduces or eliminates the need for machining.

5. Die Casting

Die casting uses high pressure to inject molten non-ferrous metals (like aluminium or zinc alloys) into reusable metal moulds, making it a staple for high-volume production.

Die casting products find their applications in automotive housings, electrical enclosures, gearbox components, and small engine parts. Die casting brings efficiency and precision to metal working where speed and volume matter.

Process Flow: 

• Molten metal is fed into a chamber.

• A hydraulic piston forces it into the mould cavity at high speed.

• The metal solidifies quickly, and the casting is ejected.

Advantages:

• Fast production with minimal post-processing.

• Consistent dimensional control and surface finish.

• Suitable for mass production of identical parts.

6. Permanent Mould Casting

Often confused with die casting, this method uses reusable metal moulds but relies on gravity (or low-pressure) rather than high-pressure injection. This process finds its applications in pistons, pump bodies, valve housings, cookware, and industrial brackets. When strength and consistency are non-negotiable, Steel Foundry turn to permanent moulds.

Process Flow:

• Molten metal is poured into the preheated metal mould.

• The mould allows uniform solidification.

• The casting is ejected once cooled, and the mould is reused.

Benefits:

• Durable moulds suitable for multiple runs.

• Good mechanical properties and surface finish.

• Less porosity and stronger casting than sand-based methods.

Making the Right Casting Choice

Casting may seem like a basic manufacturing process, but beneath the molten metal lies a world of technical choices. Each casting technique, whether it’s the classic green sand or high-precision investment casting, brings its own advantages, costs, and design freedoms.

Choosing the right method comes down to aligning with your product goals, material constraints, and production volumes. Whether you’re working with stainless steel, aluminium, or ductile iron, modern metal working demands that you cast smart.

Sujan Industries: Crafting Excellence in Every Pour

At Sujan Industries, we don’t just cast parts, we cast trust, precision, and performance. As one of India’s most experienced and reputed stainless steel casting manufacturers in India, we bring over four decades of engineering heritage to the table.

We offer end-to-end solutions for clients across the globe, serving automotive, defence, marine, and rail sectors with unwavering quality.

Looking for reliable casting partners who understand your industry? Contact our specialists today.