Investment Castings
Investment casting (lost-wax casting) forms a ceramic shell around a wax pattern, melts the wax out and pours metal into the cavity, producing complex, near-net-shape parts with fine detail and good surface finish. It is widely used for stainless steel, alloy steel and superalloy components.
What it is
Wax patterns are injected into a metal die, assembled on a tree, dipped repeatedly in ceramic slurry and stucco to build a shell, then dewaxed and fired. Molten metal fills the shell, which is broken away after cooling.
Because the pattern is destroyed, very complex shapes, thin walls and fine details are possible with little or no machining.
Typical applications
- Pump and valve components
- Impellers and turbine-type parts
- Food and pharma equipment parts
- Levers, brackets and linkages
- Medical, defence and aerospace parts
Suitable materials
- Stainless steel (CF8, CF8M, 17-4 PH)
- Carbon and alloy steels
- Tool steels
- Nickel and cobalt alloys
- Copper alloys
Points to consider
- Wax die cost is moderate; economical from a few hundred parts per year.
- Near-net shape reduces machining, especially on hard-to-machine alloys.
- Minimum wall thickness is typically around 1.5–2 mm.
- Specify material certificates and any NDT (radiography, DP) needed.
Frequently asked questions
What is the difference between investment casting and sand casting?
Investment casting gives much better detail, accuracy and finish on smaller parts; sand casting is cheaper for large parts and low volumes.
Is investment casting the same as lost wax casting?
Yes. Both names describe the same process of building a ceramic shell around a wax pattern that is melted out.
Which materials can be investment cast?
Stainless and carbon steels, alloy and tool steels, nickel and cobalt alloys, and copper alloys are common.