Investment Casting from the Investment Castings Experts

Dean Group - the History.

Established since 1972, Dean Group International (DGI) are UK manufacturers of investment castings. Formerly known as MIC, the company is market focused and rebranded successfully 2 years ago with a brand new web site.

Still privately owned, the company has grown significantly in recent years through a proactive marketing approach and a clear focus on providing the service and quality levels that our customer’s demand, at highly competitive prices.

One of the main drivers for the rebrand is that DGI have been developing supply partnerships with Far East companies since the year 2000, and this has lead to a natural progression to supply of other types of product. Whilst investment castings (IC) are still the largest part of the business, we now also source other types of product such as commercial grade IC, sand castings, die castings and any number of additional processes including machining, heat treatment, plating and polishing.

Investment Casting Process

The process commences with the production of high quality wax patterns from aluminium injection tooling. These are mounted onto a wax runner system and the assembly dipped, or invested, into ceramic slurry. The process is repeated several times until the appropriate shell thickness is produced.

On completion, the mould is de-waxed using high pressure steam leaving an empty shell. The shell is then fired to give it mechanical strength and the molten metal poured in- this could be aluminium, brass, carbon or stainless steel; virtually any metal can be produced. The shell is then allowed to cool and removed using vibration and mechanical means such as tumble or hand shot blasting.

Castings are cut from the runner system, heat treated (when required) and finished including machining, plating etc before they are final inspected. NDT (non destructive testing) and full traceability can also be offered but castings are always supplied with C of C (certificate of conformity), inspection report and chemical analysis.

This process uses only the finest quality raw material to create fine tolerances, good surface finishes and repeatable castings in a wide range of cast materials sizes and shapes. Investment castings are “precision castings”.

Product development

Whether you want an investment casting, sand casting or die casting, we can work from basic information. Send your drawing data, ideas or sample to us for evaluation – from this we can provide a budget price. This is a free service and may help you to establish whether your idea is commercially viable. With our years of experience, we will evaluate your part and offer the best solution- this may be investment casting but could equally be one of our other processes.

We would generally look to arrange a meeting at this stage, either at DGI or your factory, to enable us to optimize the design whilst retaining the key fit and functions of the part.

If the part is to be an investment casting we have the option to produce UK or with one of our supply partners- there are a number of points that affect this decision but the key ones are volume, lead time, size of part and cost.

Once we have reached design freeze we can produce CAD 3D models to allow us to produce the following:

• First stage CAD casting simulations, to ensure that we achieve a sound casting.
• Realistic casting prices from our UK foundry; or investment castings or other process from our overseas supply partners.
• Produce a firm priced quote for you.

If required, fast prototype parts can be produced in a number of ways, or the decision may be to go straight to hard tooling.

Once an order has been placed and tooling ordered, firm lead times will be confirmed. Tooling is invoiced 50% with order with the balance payable on sample approval.

In summary, your parts may have passed FEA but this does not necessarily mean they will make good castings... unless your designer has had considerable experience in investment casting design it is unlikely that you will achieve a sound casting design. If the design is not correct at the outset, it will ALWAYS be wrong and this will affect everything from aesthetic appearance, functional quality, production fallout will mean that deliveries will be variable, internal rejects will be higher, your deliveries to your customer will be late which will ultimately affect your reputation and profits.

Quality control

DGI, and our supply partners, are ISO9001-2008 accredited and can provide full material traceability to National Standards. We will produce our own inspection plans or work with customer specific Inspection Plans, Capability Studies & FMEA's for investment castings or other types of product.

At DGI we have co-ordinate Measuring Machine (CMM) facility, harness testing and mass spectrometer for chemical over checks. Quality is designed into our castings, in fact all our castings, with a philosophy that if we get the part right, it will stay right.

All parts supplied, whether from our UK investment casting facility or from one of our supply partners come with inspection report and C of C and chemical analysis as standard; all levels of NDT can be provided at additional cost including full traceability.

Contact us now about all your investment casting requirements.>