Investment Casting — Lost Wax Precision Castings
Investment casting (lost wax) is the process for complex, near-net-shape metal parts that need tight tolerance and a good surface finish. It removes most of the machining, which is why it wins on parts that would otherwise cost too much to machine from solid.
When Investment Casting Is the Right Choice
Choose lost wax casting when your part has complex geometry, thin walls, or a surface finish that sand casting cannot hold. Because the pattern is a wax replica, you get shapes that are impossible to machine in one piece — internal channels, fine details, near-net profiles.
| Parameter | Typical capability |
|---|---|
| Materials | Stainless steel (304/316), carbon steel, alloy steel, tool steel |
| Part weight | 10 g – 60 kg |
| Dimensional tolerance | CT5 – CT7 (GB/T 6414), typically ±0.15% of dimension |
| Surface finish | Ra 3.2 – 6.3 µm as-cast |
| Minimum wall | Down to 1.5 – 2 mm |
Materials
| Family | Common grades | Typical use |
|---|---|---|
| Stainless steel | 304, 316, 316L, 17-4PH | Valve bodies, impellers, food & chemical fittings |
| Carbon / alloy steel | WCB, 42CrMo, 40Cr | Housings, levers, brackets, couplings |
| Tool steel | H13, P20 | Dies and wear parts |
Why It Reduces Total Cost
The unit price of investment casting is higher than sand casting, but the total landed cost is often lower: less machining, less material waste, fewer operations. If you are currently machining a complex part from billet, lost wax is usually worth quoting.
Inspection & Documents
- Spectrometry material certificate
- X-ray / dye penetrant / magnetic particle on request
- Dimensional inspection against drawing
- Heat treatment records
Lead Time & MOQ
- Tooling (wax die): 10–20 天
- Sample: 20–30 天
- Production: 25–40 天
- MOQ: 50 pcs
FAQ
Is investment casting more expensive than sand casting?
Per part, usually yes — the wax pattern and shell add steps. But on complex parts the savings in machining often make the finished-part cost lower. We quote both so you can compare on total cost, not unit price.
What tolerance can I expect?
Typically CT5–CT7, about ±0.15% of the dimension. We confirm the achievable tolerance against your drawing before quoting.
Can you machine and finish the casting?
Yes, machining and surface finishing are done in-house, so you receive a finished, inspected part.
Send your drawing, quantity and target delivery date.
Related: Sand Casting · Die Casting · Machined & Finished Castings · All Castings
