Investment Casting
Investment casting, also called lost-wax casting, builds a ceramic shell around a wax pattern, melts the wax out and pours metal into the cavity. Its main advantage is producing complex shapes in steel and stainless steel — materials that die casting cannot handle — often as a single piece instead of a welded assembly.
Typical investment cast parts
- Valve bodies, pump parts and impellers
- Levers, brackets, fittings and couplings
- Complex stainless parts that would waste a lot of material if machined from solid
- Welded assemblies that can be consolidated into one casting
Stainless steel and steel grades
| Group | Common grades | Japanese equivalent |
|---|---|---|
| Austenitic stainless | CF8 (cast 304), CF8M (cast 316), CF3 / CF3M | SCS13, SCS14, SCS19A, SCS16A |
| Martensitic / PH stainless | CA15, CB7Cu-1 (17-4PH) | SCS1, SCS24 |
| Carbon and low-alloy steel | WCB, 1020–1045, 4140 equivalents | SC, SCPH, SCM equivalents |
Cast grades (e.g. CF8M) and wrought grades (e.g. 316 bar) are covered by different standards even when the chemistry is similar. Specify the grade and standard on the drawing.
Investment casting vs other processes
| Investment casting | Die casting | Machining from solid | |
|---|---|---|---|
| Materials | Steel, stainless, some non-ferrous | Aluminum, zinc and other non-ferrous | Almost anything |
| Tooling | Lower than die casting | Higher | None |
| Quantity | Low to medium | Medium to high | Prototype to low |
| Strength | Complex, consolidated shapes | Thin walls at high volume | Precision surfaces |
Precision faces are normally machined after casting. More in investment casting vs die casting vs sand casting.
FAQ
When should I choose investment casting over die casting?
If the part must be steel or stainless, or quantities are too low to justify a die casting die, investment casting is usually the candidate. Send quantity, material and geometry and we will suggest a route.
Can you include heat treatment and machining?
Yes. Heat treatment, machining and finishing are included in the quotation when the drawing requires them.