Investment Casting

Dean Group / Services / Investment Casting
At Dean Group, we’ve been perfecting the art and science of investment casting since 1972. Trusted by leading industries worldwide, our experience, technical expertise, and commitment to quality ensure we deliver precision components that perform exactly as you need.

Lost Wax Casting

Also known as lost wax casting, investment casting allows us to transform your designs into precision-engineered components with exceptional repeatability. 

Using a detailed wax pattern, we build a robust ceramic shell around it. Once the wax is removed, molten metal is poured into the shell, cooled, and finished to your exact specifications.

We combine traditional foundry craftsmanship with cutting-edge technology such as 3D printing for rapid prototyping, enabling faster development, testing, and production. Every part is inspected to rigorous quality standards, giving you complete confidence in both performance and reliability.

Investment casting process diagram

The Investment Casting Process

Investment casting uses a hard refractory ceramic mould to produce parts with much tighter tolerances than other methods, such as sand casting. In sand casting, the mould must be broken apart to remove the part, often leaving a rough surface. By contrast, investment casting delivers a smooth finish with only a minimal parting line, typically requiring little to no secondary processing such as polishing or trimming.

3D Printed Wax

A wax pattern needs to be created in order to form the end-cast product. Usually, this is done with tooling or dies, but in this case, we can negate the need for tooling and 3D printing directly into wax from a 3D model. This process allows for quick and accurate prototype product manufacture for trial testing and review.

Wax Assembly

Once the wax patterns have been created, either from prototype 3D printing or tooling for casting, we would then need to assemble them into something commonly known as a ‘tree’. This tree comprises multiple wax patterns attached to its exterior. The more wax patterns you can attach to the exterior, the more efficient a tree is. You would get many wax patterns on one tree if they were small; you would only get a few if they were larger.

Investment

Investment casting got its name from this stage of the process; this is the process where you investment in material to form a shell. We form this shell by submersing the now assembled tree into a specially designed slurry mixture. This slurry mixture is a semi-viscous adhesive, which we then cover in a special sand. Then, left to dry, the process is repeated a number of times to build up a thick shell that is permeable to air but can withstand immense temperatures and hold molten metal.

Wax Removal

The wax tree is now fully encased in a thick and durable shell. The wax has now done its job and needs to be removed to reveal a hollow cavity. To do this, we need to go through a special process of heat and pressure. We load several trees into something called a Boilerclave. This piece of kit applies the required heat and pressure to cause the wax inside the trees to melt and exit out of the shell, leaving behind a hollow negative impression, generally known as the mould.

Firing

Firing the trees does two things: it fully bakes the shell to meet the required toughness required to withstand handling and pouring. The second is to bring the temperature closer to the temperature of what the metal would be. Metal is poured into the shell at around 1600-1700°C. If this were to be done in a shell at room temperature, then something called ‘Thermal shock’ would happen, which would cause shell failure. By bringing the shell up to 1000°C, the issue of thermal shock is removed, and the products are in full form once cast.

Casting

Metal ingots are added into a furnace, melted and brought up to a castable temperature of around 1600-1700°C. The shell is removed from the oven and brought over to the waiting molten metal. The metal is poured into the shell, which fills the internal voids with molten metal. Once cast, it is put to the side to cool down and solidify.

Fettling

Once the tree has cooled down to room temperature, we need to remove the shell from the exterior. This is usually done by high-force impact or sometimes by water blasting. Once the shell has been removed, the fully formed metal casting will be revealed. At this point, they are still attached to the tree and need to be removed. They are removed from the tree with various saws and plasma cutters. Finally, they are ground back to a finished cast state as per customer requirements.
Finished Casting
Once fettled, castings can undergo multiple post-process treatments such as shot blasting to improve surface finish, heat treatment to improve mechanical strengths, machining to meet higher tolerances and much more. Castings are versatile items that can meet many customer requirements.

Why Choose Dean Group?

Over 50 Years of Specialist Experience

Investment casting is ideally suited to smaller, more intricate designs and provides the precision necessary to incorporate logos, product IDs and numbers onto the surface.

Unlike sand casting, which requires breaking apart the mould to divest the pattern, the investment casting process results in a smoother surface with only a minor parting line. Investment casting generally does not need much secondary processing (polishing, trimming, etc.). Investment casting uses hard refractory ceramic, creating finished parts with much tighter tolerances than sand casting.
A summary of investment casting benefits can be seen below:

You Can Add Text, Logos and Numbers

Customise parts with your company name, logo, serial number, and more. Ideal for small, complex parts, offering flexibility and precision.

Allows for Repeatability

Ensures consistency and repeatability with virtually no tool wear. Reliable, cost-efficient, and produces error-free parts with exact dimensions

Benefit from Secondary Operations

While highly precise, parts can be enhanced with additional processes like annealing and tempering to improve properties such as strength and hardness.

Reduced Assembly Work

Minimises assembly work, allowing for quicker turnaround. Combines multiple parts into a single casting, saving time and money.

Cost-Effective Production

Achieve complex geometries without expensive secondary machining.

Non-Destructive Testing

Ensures quality through mechanical, chemical, X-ray, and ultrasonic testing. Techniques like microscopy and spectroscopy prevent material damage.

Our Services

From ferrous to non-ferrous metals and to other exotic metals, we can design and volume manufacture investment castings to a wide range of design specifications.

Premium Grade Investment Casting

Commercial Grade Investment Casting Service

We also offer a commercial grade investment casting service, which offers design flexibility and good cast integrity. This process is ideal for larger and less intricate designs with capabilities to cast parts up to 100kgs. It is also best suited for medium to large-volume runs with virtually no tool wear and overall reduced production costs.
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Premium Grade Investment Casting

Premium Grade Investment Casting Service

Our premium grade investment casting is suitable for several applications, including the manufacturing of complicated shapes that can’t be produced with other methods. This method can cast individual parts up to 30kgs with 1000 x 620 x 380 (mm) dimensions. It is highly accurate and consistent, perfect for both low and high-volume production.
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Elite Aluminium Casting

Elite Grade Investment
Casting Service

The aluminium investment casting (ELITE) process allows for a range of part sizes and weights to be cast with excellent mechanical properties. It also produces parts with an enhanced microstructure that are gas-tight, and there is also no need for ‘HIP’.
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We have a fully equipped UK foundry based in Manchester that manufactures excellent made-in-UK castings. We also have reliable international supply chain sourcing operations in China and India coupled with UK stock holding facilities to overcome extended lead times from overseas, enhancing our manufacturing capabilities.
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Frequently Asked Questions

Investment casting, also called the lost wax process, is a metalworking technique used to create detailed and complex metal parts. It starts with making a wax model of the part, which is coated in ceramic to form a shell. When the wax melts away, molten metal is poured into the shell, producing precise metal components after cooling and finishing.

The name “investment casting” comes from the process of “investing,” or coating, the wax model with a ceramic material. This creates a mould after the wax is melted out, hence it’s also known as the lost wax casting process.

Investment casting can use almost any metal that melts and pours well. Common materials include stainless steel, carbon steel, aluminium alloys, copper and brass alloys, cobalt alloys, Inconel, and custom alloys. Dean Group can work with a wide range of metals based on your needs.

Investment casting is a bespoke process; each project comes with its own unique pricing. It is the most commercially effective way to produce complex parts in various alloys on a large scale. There are cheaper casting processes, but this will be at expensive of quality, material & overall finish.

Investment casting is perfect for producing highly detailed, complex metal parts that other methods can’t achieve. It’s widely used in industries like aerospace, defence, railway, and medical because it delivers precision parts with minimal finishing required

Investment casting offers high precision, tight tolerances, and smooth surface finishes, often reducing or eliminating the need for machining. It’s ideal for creating intricate shapes, delivers consistent results for any batch size, and can have turnaround times as fast as three to four weeks. The main thing that varies is cost as it’s more complex than simpler methods like sand casting, especially for large parts. For bespoke projects where accuracy and detail matter, the benefits often outweigh the difference in costings.

Contact Dean Group International for Your Investment Casting Quote

To find out more about our investment casting, or to get a quote for your project, please get in touch with us on 0161 775 1633 or submit your enquiry online.
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