Investment castings by the lost-wax process
Dimensionally accurate castings from 0.1 to 120 kg — tight tolerances and smooth surfaces without secondary machining.
In investment casting a wax pattern is repeatedly dipped in ceramic slurry until a load-bearing shell forms. The wax is melted out, the shell is fired and filled with molten metal. Because the mould is seamless and has no parting line, investment casting achieves tolerances and surfaces that other casting processes cannot — frequently without any machining at all.
We supply investment castings from 0.1 to 120 kg per piece in stainless steel, carbon steel and special alloys. The process pays off particularly for complex geometries in medium to high quantities: thin walls from 3 mm, internal passages, cast-in functional faces. Tooling cost applies to the wax injection die and normally amortises through the machining it saves.
Technical data
| Piece weight | 0.1 – 120 kg |
|---|---|
| Wall thickness | from 3 mm |
| Tolerances | CT5 – CT7 to ISO 8062 |
| Surface roughness | Ra 3.2 – 6.3 µm |
| Process | Lost-wax process (ceramic shell) |
| Tooling | Wax injection die, customer property |
| Testing | X-ray, PT, spectrographic analysis, dimensional report |
These are typical manufacturing ranges within our supplier network. Larger dimensions and special materials on request — send us your drawing.
Materials
- 1.4408 / CF8M
- 1.4308 / CF8
- 1.4581
- GS-52 / carbon steel
- Duplex 1.4470
- Nickel-base alloys on request
Manufacturing and quality assurance
- Wax injection die built to your 3D geometry, including shrinkage allowance for the target alloy.
- Ceramic shell built up in several dipping and stuccoing steps with controlled drying.
- Pouring into the preheated shell — which improves mould filling in thin sections.
- First article inspection with a full dimensional report against your drawing before series release.
- X-ray and dye penetrant testing as agreed, spectrographic analysis per heat.
Typical applications
- Valve components and valve bodies
- Pump impellers and guide vanes
- Components for food and pharmaceutical equipment
- Process engineering parts
- Turbine and compressor components
- Complex brackets and levers
Frequently asked questions
From what quantity is investment casting worthwhile?
Usually from a few hundred pieces per year, because the wax injection die has to be financed. For complex parts that would otherwise require extensive machining, however, the process can pay off at considerably smaller volumes.
What tolerances does investment casting achieve?
Typically CT5 to CT7 to ISO 8062, which is already sufficient for many functional surfaces. Fits and sealing faces are still finish-machined, but the effort is a fraction of what sand casting would require.
How thin can the walls be?
From around 3 mm in series production; thinner sections are possible depending on alloy, flow length and part size. For thin-walled geometries we verify mould filling in advance.
Who owns the wax injection die?
Tooling paid for by the customer remains the customer's property. Location and condition are documented and the tool is released on request.
Investment casting or sand casting for my part?
Investment casting for smaller, complex parts with tight tolerances and smooth surfaces. Sand casting for large components, heavy sections and small quantities. We compare both routes including machining effort in the quotation.
Request a quote for Investment castings
Send us your drawing or specification. You get feedback on feasibility, material selection and an indicative price — from engineers, not from a call centre.
Send enquiry