Are you looking to improve product quality while reducing production costs? The casting method you choose plays a bigger role than you might think.

Each casting process—from sand casting to investment casting—has unique advantages and limitations. Some are ideal for large, simple parts. Others are perfect for detailed, precision components. If you’re not familiar with the 10 casting processes used in modern manufacturing, you might end up choosing the wrong one.

By understanding each process, you can significantly lower your defect rate, optimize machining time, and reduce overall costs. Whether you’re producing small batches or scaling to mass production, the right casting method saves time and money.

In this article, I’ll introduce the 10 casting processes I work with in our metal production lines. I’ll explain how each works, where it fits best, and how you can use this knowledge to make better buying decisions.

1. Sand Casting: Low Cost, High Flexibility

1.1 What Is Sand Casting?

Sand casting is one of the most traditional methods among the 10 casting processes. It uses sand mixed with clay or binders to form a mold. Molten metal is poured into this mold, allowed to solidify, and then the mold is broken apart to retrieve the finished part.

1.2 Advantages of Sand Casting

• Low Cost of Tooling – Sand molds are inexpensive compared to permanent molds.
• Material Flexibility – Almost any metal, including steel, aluminum, and bronze, can be cast.
• Adaptability – Works well for both small and very large parts.
• Short Development Cycle – Prototypes can be produced quickly.

Example: In my factory, we often use sand casting for agricultural machinery, mining equipment components, and large industrial bases where cost efficiency is essential.

1.3 Disadvantages of Sand Casting

While sand casting is versatile, it does have drawbacks:

• Surface Roughness – The sand grains leave a textured finish.
• Lower Precision – Tolerances are wider compared to die casting or investment casting.
• Single-Use Mold – Each sand mold can only be used once, making high-volume production slower.

1.4 When to Choose Sand Casting?

Sand casting is best suited when:

• You need low-cost production for medium or large parts.
• The final product can tolerate some machining.
• Production volume is moderate rather than extremely high.

2. Die Casting: High-Speed Precision

2.1 What Is Die Casting?

Die casting is one of the most widely used methods in the 10 casting processes when it comes to producing large volumes of small to medium-sized metal parts with high accuracy. The process involves forcing molten non-ferrous metal—such as aluminum, zinc, or magnesium—into a hardened steel mold (called a die) under very high pressure. Once the metal solidifies, the die opens, and the part is ejected. Because the mold can be reused thousands of times, die casting is excellent for mass production.

2.2 Advantages of Die Casting

• High Dimensional Accuracy – Parts can achieve tight tolerances, often requiring little to no machining.
• Excellent Surface Finish – Smooth surfaces are possible, reducing finishing work.
• High Production Rate – Fast cycle times allow for thousands of castings daily.
• Thin Wall Sections – Enables the creation of lightweight parts with complex geometries.
• Reusable Molds – Steel dies last long and allow consistent quality.

Example: In my production lines, die casting is often chosen for automotive housings, electronic enclosures, and consumer hardware where both precision and appearance are critical.

2.3 Disadvantages of Die Casting

While powerful, die casting has its challenges:

• High Initial Tooling Cost – Making the die is expensive, so it only pays off in high-volume production.
• Material Limitation – Generally limited to non-ferrous alloys like aluminum, zinc, and magnesium.
• Porosity Risk – Gas trapped during injection can create small voids, affecting strength.
• Not Suitable for Very Large Parts – Size is restricted by the die and injection system.

2.4 When to Choose Die Casting?

Die casting is the best option when:

• You need high-volume production of identical parts.
• Dimensional accuracy and surface finish are critical.
• You are working with aluminum, zinc, or magnesium alloys.
• The budget allows for high tooling investment, which pays off over thousands of cycles.

3. Investment Casting: Complex Shapes, Fine Detail

3.1 What Is Investment Casting?

Investment casting, also known as lost-wax casting, is one of the most precise methods among the 10 casting processes. The process begins with creating a wax pattern of the desired part. This wax model is repeatedly dipped into a ceramic slurry to build a hardened shell. Once the ceramic coating is strong enough, the wax is melted and drained out, leaving a hollow cavity. Molten metal is then poured into the cavity, solidified, and the ceramic shell is broken away to reveal the final casting.

This method has been used for thousands of years, but modern technology has improved it with better waxes, ceramics, and alloys, making it suitable for advanced industries today.

3.2 Advantages of Investment Casting

• High Precision – Tolerances are excellent, reducing the need for machining.
• Smooth Surface Finish – Parts require little to no secondary finishing.
• Complex Shapes – Capable of producing thin walls, intricate details, and undercuts.
• Material Flexibility – Works with a wide range of ferrous and non-ferrous alloys.
• Near Net Shape – Saves material waste compared to machining from solid blocks.

Example: In my factory, we use investment casting for valve components, aerospace brackets, turbine blades, and medical instruments where precision is non-negotiable.

3.3 Disadvantages of Investment Casting

Despite its advantages, investment casting also has limitations:

• Higher Cost per Part – More expensive than sand casting, especially for large parts.
• Longer Lead Times – The process of creating wax models and ceramic shells takes time.
• Size Limitations – Best for small to medium-sized parts, not massive structures.
• Shell Fragility – Ceramic molds are delicate and require careful handling.

3.4 When to Choose Investment Casting?

Investment casting is best when:

• You need high precision and fine detail in your parts.
• The product design includes thin walls, undercuts, or intricate geometries.
• Production runs are low to medium volume, where cost per part is acceptable.
• Surface quality is a priority, minimizing post-machining costs.

4. Shell Molding: Hybrid Between Sand and Investment

4.1 What Is Shell Molding?

Shell molding, sometimes called shell mold casting, is a semi-precision process within the 10 casting processes. It uses fine-grain sand that has been coated with a thin layer of thermosetting resin. The coated sand is heated and applied to a pre-heated metal pattern, forming a thin, hard “shell” mold layer. Several layers are built up until the mold is strong enough. The two halves of the shell mold are then assembled, molten metal is poured in, and once it solidifies, the shell is broken away.

This process is essentially a hybrid between traditional sand casting and investment casting. It offers higher precision and surface finish than regular sand casting, but with lower cost and faster cycle times compared to investment casting.

4.2 Advantages of Shell Molding

• Better Accuracy – Tighter tolerances than sand casting.
• Improved Surface Finish – The resin-coated sand provides smoother results.
• Lower Tooling Cost vs. Investment Casting – More affordable for medium volumes.
• Automation Friendly – Easier to adapt for mechanized production lines.
• Less Machining Required – Parts often come closer to net shape.

Example: In my production practice, we often recommend shell molding for gear housings, pump bodies, engine brackets, and motor components where a balance of cost and precision is needed.

4.3 Disadvantages of Shell Molding

Even though shell molding is highly versatile, it has a few drawbacks:

• Higher Material Cost – Resin-coated sand is more expensive than regular sand.
• Single-Use Mold – Like sand casting, each shell can only be used once.
• Size Limitations – Not suitable for very large parts.
• Processing Equipment – Requires heating units and handling systems for coated sand.

4.4 When to Choose Shell Molding?

Shell molding is ideal if:

• You need better precision than sand casting but want to avoid the high cost of investment casting.
• Production volume is medium scale, where reusable metal dies would not be cost-effective.
• The part requires a smoother finish with less post-processing.
• Complex but not extremely intricate shapes are required.

5. Centrifugal Casting: Best for Hollow Parts

5.1 What Is Centrifugal Casting?

Centrifugal casting is one of the most specialized methods within the 10 casting processes, used primarily to produce hollow or cylindrical parts. In this process, molten metal is poured into a mold that rotates at high speed. The centrifugal force pushes the molten metal against the mold wall, ensuring uniform distribution and high density. As the metal solidifies under rotation, impurities and lighter inclusions are forced toward the inner surface, where they can later be machined away.

This makes centrifugal casting particularly useful for applications requiring strength, density, and excellent mechanical properties. Unlike many other casting methods, it does not rely heavily on gating and risers, which reduces waste and improves yield.

5.2 Advantages of Centrifugal Casting

• High Structural Integrity – The centrifugal force compacts the metal, reducing porosity.
• Excellent Mechanical Properties – Parts are stronger and more reliable.
• Good for Symmetrical Shapes – Particularly effective for tubes, pipes, and bushings.
• Reduced Impurities – Lighter inclusions are separated from the outer surface.
• Cost-Effective for Specific Shapes – Saves machining time for hollow parts.

Example: In my experience, centrifugal casting is often used for pipes, sleeves, cylinder liners, and bushings where durability and resistance to stress are vital.

5.3 Disadvantages of Centrifugal Casting

Despite its strong benefits, centrifugal casting has some limitations:

• Shape Limitation – Only suitable for cylindrical or round geometries.
• High Equipment Cost – Requires specialized rotating machinery.
• Not Suitable for Complex Parts – Cannot be used for intricate or irregular shapes.
• Size Restriction – Large diameters can be challenging to cast consistently.

5.4 When to Choose Centrifugal Casting?

Centrifugal casting is ideal if:

• You need hollow, cylindrical, or tubular components.
• Mechanical strength and structural integrity are top priorities.
• You are working with ferrous or non-ferrous alloys where porosity reduction is critical.
• Production volume justifies investment in specialized equipment.

6. Lost Foam Casting: Innovative and Efficient

6.1 What Is Lost Foam Casting?

Lost foam casting is one of the more modern innovations in the 10 casting processes. It uses a foam pattern made from polystyrene, which is coated with a refractory material to form a mold. When molten metal is poured into the mold, the foam pattern vaporizes and disappears, leaving behind the metal part in its exact shape.

This process eliminates the need for cores, parting lines, or complex mold assembly. Because the foam pattern is destroyed during casting, every part requires a new foam model. Although this increases pattern cost, the resulting accuracy and simplicity of mold preparation make lost foam casting very attractive for certain industries.

6.2 Advantages of Lost Foam Casting

• Excellent Shape Complexity – Produces complex geometries with ease.
• No Parting Line – Results in smoother surfaces and less finishing.
• Reduced Core Requirement – Simplifies mold design compared to sand casting.
• High Dimensional Accuracy – Less machining required.
• Efficient for Prototyping – Quickly turns 3D foam patterns into functional parts.

Example: In my production work, lost foam casting is often selected for engine blocks, automotive housings, pump parts, and prototypes where complex internal geometries are needed.

6.3 Disadvantages of Lost Foam Casting

Lost foam casting does have some drawbacks:

• Foam Pattern Cost – Each part requires a new foam pattern, adding expense.
• Environmental Concerns – Foam decomposition produces gases that must be controlled.
• Process Sensitivity – Requires careful handling to avoid defects in coating or pouring.
• Limited Industry Adoption – Less common compared to sand or die casting, meaning fewer suppliers.

6.4 When to Choose Lost Foam Casting?

Lost foam casting is the right choice when:

• Your design has complex internal features that would be costly with cores.
• You want to eliminate parting lines for smoother finishes.
• Production is low to medium volume, where pattern costs are manageable.
• Prototyping or experimental designs require flexibility and accuracy.

7. Permanent Mold Casting: Durable Reusable Molds

7.1 What Is Permanent Mold Casting?

Permanent mold casting is a key method in the 10 casting processes that uses reusable metal molds, usually made of steel or cast iron. Unlike sand or shell molding, the mold in this process is not broken after each use but can be employed repeatedly to produce hundreds or thousands of parts.

The molten metal is poured into the preheated mold either by gravity, low pressure, or even centrifugal force. Once solidified, the mold is opened, and the part is removed. Because the mold can be reused, permanent mold casting achieves greater consistency, tighter tolerances, and better surface finishes compared to disposable-mold methods.

7.2 Advantages of Permanent Mold Casting

• Reusable Molds – Reduces per-part cost in medium to high volumes.
• Better Surface Finish – Parts often require minimal machining.
• Dimensional Consistency – High repeatability across batches.
• Mechanical Strength – Cooling rates are faster, leading to finer grain structures.
• Suitable for Automation – Well-suited to mechanized or semi-automated production.

Example: In my factory, permanent mold casting is widely used for aluminum automotive parts, gearbox housings, and small structural components where surface finish and dimensional control matter.

7.3 Disadvantages of Permanent Mold Casting

Although it offers many benefits, permanent mold casting has its challenges:

• High Initial Mold Cost – Metal molds are more expensive than sand molds.
• Size Limitation – Large parts are impractical due to mold handling constraints.
• Limited Alloy Range – Best suited for non-ferrous alloys such as aluminum, magnesium, and copper.
• Less Design Flexibility – Complex shapes with undercuts are difficult to produce.

7.4 When to Choose Permanent Mold Casting?

Permanent mold casting is best suited when:

• You require medium to high production volumes of the same part.
• The design is relatively simple but requires precision.
• Surface finish and dimensional consistency are priorities.
• You are working with aluminum or other non-ferrous alloys.

8. Low-Pressure Casting: Controlled Filling for Stronger Parts

8.1 What Is Low-Pressure Casting?

Low-pressure casting is a widely used method within the 10 casting processes, especially in the automotive industry. In this process, molten metal is forced upward into a mold using low pressure (usually between 0.3–1.5 bar). Unlike gravity casting, which lets the metal flow naturally, the controlled pressure ensures that the mold cavity fills more smoothly and evenly.

This results in parts with better dimensional accuracy, reduced porosity, and higher mechanical strength. Because the molten metal is drawn from the furnace bottom rather than poured from above, the chances of oxidation and turbulence are significantly reduced.

8.2 Advantages of Low-Pressure Casting

• Excellent Metallurgical Quality – Fewer gas defects, less porosity.
• Higher Yield – The process minimizes gating and riser waste.
• Dimensional Accuracy – More precise than sand or permanent mold casting.
• Stronger Parts – Fine grain structure due to controlled solidification.
• Efficient for Aluminum Alloys – Especially suitable for lightweight structural parts.

Example: In my experience, low-pressure casting is widely applied for automotive wheels, suspension parts, and aerospace components, where safety and strength cannot be compromised.

8.3 Disadvantages of Low-Pressure Casting

Even though this method is highly efficient, it has some drawbacks:

• Higher Equipment Investment – Requires a pressurized furnace and specialized mold setup.
• Slower Cycle Time – Not as fast as die casting for high-volume runs.
• Limited Alloy Range – Best suited for non-ferrous alloys like aluminum and magnesium.
• Size Constraints – Large molds may be difficult to control under pressure.

8.4 When to Choose Low-Pressure Casting?

Low-pressure casting is the best choice when:

• You need structurally strong and defect-free aluminum components.
• Medium to high production volumes are expected.
• The product is safety-critical, such as automotive or aerospace applications.
• You want a balance of quality, efficiency, and cost-effectiveness.

9. Vacuum Casting: High-Quality Finish with Minimal Defects

9.1 What Is Vacuum Casting?

Vacuum casting is one of the most advanced techniques among the 10 casting processes. In this method, molten metal is poured into a mold under vacuum conditions. By removing the air inside the mold, the process minimizes turbulence and gas entrapment, which are common causes of porosity and internal defects in cast parts.

This technique is especially useful for producing parts that require exceptional surface quality, structural integrity, and reliability. Vacuum casting is widely used not only for metals but also for plastics in rapid prototyping, though in the context of metal fabrication it refers to vacuum-assisted metal pouring.

9.2 Advantages of Vacuum Casting

• Minimal Porosity – Gas defects are greatly reduced thanks to the vacuum environment.
• Superior Surface Finish – Produces smooth, defect-free surfaces.
• Enhanced Mechanical Properties – Stronger, denser castings due to fewer inclusions.
• Excellent for Thin-Walled Parts – Ensures proper mold filling without turbulence.
• Consistency – High reliability for safety-critical applications.

Example: In my factory, we recommend vacuum casting for aerospace components, defense equipment, turbine blades, and medical devices where failure is not an option.

9.3 Disadvantages of Vacuum Casting

Despite its benefits, vacuum casting also has limitations:

• High Equipment Cost – Requires vacuum chambers and specialized molding systems.
• Slower Production Cycle – Not ideal for mass production of low-value parts.
• Complex Setup – Needs trained operators and controlled conditions.
• Higher Per-Part Cost – Best reserved for high-value applications.

9.4 When to Choose Vacuum Casting?

Vacuum casting is the right choice when:

• The parts must have exceptional quality and reliability.
• You are producing aerospace, medical, or defense components.
• Surface finish and mechanical strength are top priorities.
• Production volumes are lower, but precision and safety are critical.

10. Continuous Casting: High Efficiency for Raw Materials

10.1 What Is Continuous Casting?

Continuous casting is one of the most industrially significant methods in the 10 casting processes. Unlike other processes designed for finished parts, continuous casting is primarily used to produce semi-finished products such as billets, slabs, blooms, and rods.

In this process, molten metal is continuously poured into a water-cooled mold, where the outer layer solidifies while the inner core remains liquid. The partially solidified strand is continuously withdrawn from the mold, fully solidifies as it passes through secondary cooling, and is cut into desired lengths. This method allows large-scale production of raw materials for further rolling, forging, or machining.

10.2 Advantages of Continuous Casting

• High Efficiency – Enables nonstop production of metal billets and slabs.
• Excellent Yield – Reduces metal waste compared to ingot casting.
• Better Metallurgical Quality – Fine grain structures with fewer defects.
• Lower Production Cost – Reduces energy consumption and handling costs.
• Uniform Product Quality – Provides consistent raw material for downstream processes.

Example: In large-scale steel and copper production, continuous casting is the standard process for producing raw material stock used in construction, automotive, and shipbuilding industries.

10.3 Disadvantages of Continuous Casting

Continuous casting also comes with limitations:

• High Capital Investment – Requires expensive, large-scale machinery.
• Not Suitable for Complex Shapes – Limited to producing simple semi-finished products.
• Maintenance Intensive – Continuous operation demands strict monitoring and regular maintenance.
• Large-Scale Only – Not economical for small-batch production.

10.4 When to Choose Continuous Casting?

Continuous casting is the best choice when:

• The goal is high-volume production of billets, rods, or slabs.
• You require uniform metallurgical quality in raw materials.
• Production is focused on steel, aluminum, copper, or other mass-market metals.
• You are operating in a large industrial environment where efficiency and yield are critical.

🔹 Comparison of 10 Casting Processes

Casting Process	Precision & Tolerance	Surface Finish	Typical Materials	Cost Level	Best Applications
1. Sand Casting	Low–Medium	Rough	Steel, Iron, Aluminum, Bronze	Low	Large parts, machinery, mining & agriculture equipment
2. Die Casting	High	Smooth	Aluminum, Zinc, Magnesium	High (tooling)	Automotive housings, electronics, consumer goods
3. Investment Casting	Very High	Excellent	Stainless Steel, Alloy Steel, Aluminum	Medium–High	Aerospace parts, valves, turbine blades
4. Shell Molding	Medium–High	Good	Iron, Steel, Aluminum	Medium	Gears, pump bodies, motor housings
5. Centrifugal Casting	High (cylindrical)	Good	Iron, Steel, Bronze	Medium	Pipes, sleeves, cylinder liners
6. Lost Foam Casting	High	Good	Aluminum, Iron, Steel	Medium	Engine blocks, complex housings
7. Permanent Mold Casting	Medium–High	Good	Aluminum, Copper, Magnesium	Medium–High	Automotive, aerospace components
8. Low-Pressure Casting	High	Very Good	Aluminum, Magnesium	Medium–High	Automotive wheels, aerospace structures
9. Vacuum Casting	Very High	Excellent	High-grade alloys (steel, titanium, aluminum)	High	Aerospace, defense, medical devices
10. Continuous Casting	Medium (semi-finished)	Medium	Steel, Copper, Aluminum	High (setup)	Billets, slabs, rods for rolling & forging

Conclusion

Choosing wisely among the 10 casting processes ensures better quality, lower costs, and the right fit for your project. Always match process to need.