Prototypes – Plaster casting

This process is used to manufacture cast prototypes and special components in aluminium, magnesium and zinc with delivery times from 5 working days.

Following the casting process, we offer CNC post-machining of the cast items on our state-of-the-art machines, including measurements and documentation.

High capacity
To ensure prompt deliveries, our setup is based on a very high capacity as well as in-house production of the entire process. Read more about the concept below.


Prototype i aluminium
Kvalitetsgaranti ved Formkon A/S

Prompt offers
Offers for casts are sent within 2-48 hours.

Kvalitetsgaranti ved Formkon A/S

Extremely fast deliveries
The first casts within 5-10 working days.

Kvalitetsgaranti ved Formkon A/S

Large degrees of freedom
Highly complex items can be produced without release angles and with undercuts.

Kvalitetsgaranti ved Formkon A/S

Thin wall thicknesses
Down to 1mm and, in some cases, even thinner.

Kvalitetsgaranti ved Formkon A/S

Very high capacity
We are able to handle large projects without compromising on delivery times.

Making plaster cast prototypes

Design of inlets, etc.
The first step is 3D design of the inlet and provisioning of machining allowances, if any, for the subsequent CNC machining. For complex items, we can also carry out casting simulations.

3D printing of PMMA models
The number of finished metal items to be used will be printed as PMMA models first. The models, including inlets, are printed on our large Voxeljet VX800 printer with a building volume of 850 x 450 x 500mm.

Plaster mould production
The 3D printed PMMA models are cast in plaster. The PMMA models are then burnt off at approximately 700 degrees in one of our 5 large industrial ovens. This forms a cavity in the plaster mould corresponding to the finished item in metal.

After burning out the PMMA model, molten aluminium, magnesium or zinc is poured into the plaster mould. We always use new materials and vacuum in the casting process to ensure a uniform and homogenous casting. When set, the plaster mould is smashed and plaster residue is washed off the cast item. The inlet is removed and the items are now ready for shipment or further machining.


When the items are cast, we can carry out complex CNC machining at our state-of-the-art machining department. In addition to CNC machining, we are also offering other types of in-house finishing such as heat treatment and impregnation.

Quality control
Before shipping the item, we can measure and check them to ensure that they fully meet the customer’s requirements. Our subcontractors also allow us to offer x-ray documentation and to carry out various types of materials tests.

Competent counselling

We have more than 30 years’ experience in producing prototypes in aluminium, magnesium and zinc. Competent counselling is crucial to our business concept. Contact us for a non-binding dialogue about your prototype needs.

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Plaster casting - technical specifications

• Aluminium AlSi7Mg – AB-42000
• Aluminium AlSi10Mg(Cu) – AB-43200
• Magnesium AZ91
• Magnesium AM50
• Magnesium AM60
• Zinc Zamak 5

Other alloys on request.

Casting tolerances according to VDG P690, Accuracy grade D1.

1-50 pcs.

700mm x 400mm x 400mm (larger items may be possible but will require further studies).

Ra 6 to Ra 9