304SS Investment Casting Services
Leesh Holdings specializes in 304SS Investment Casting for precision stainless steel components — bleed rings, integrated flanges, pipe fittings and valve parts. From wax tooling to finished machined parts, each piece is delivered with full material certification.
What Is 304SS Investment Casting?
304SS Investment Casting is the lost-wax casting route for 304-grade stainless steel — a process that reproduces complex contours, thin walls and tight internal passages in one near-net-shape pour. Unlike sand casting, it needs no draft angles on small features, which is why fittings and rings with sealing surfaces are typically investment cast.
Near-Net-Shape Economy
Machining allowance as low as 0.5–1.0 mm — most of the metal stays in the part, not the scrap bin.
Intricate Geometries
Bleed ports, undercuts and thin fins that sand molding cannot achieve, cast in one piece.
Sealing-Surface Ready
Smooth as-cast finish minimizes stock removal on flanges and sealing faces.
Batch Traceability
Every heat tracked with spectro chemistry and mechanical test records.
304SS Casting Chemistry
The cast analysis of 304SS matches the familiar 18/8 austenitic recipe — the same family as CF8 per ASTM A351.
| Element | Content (%) | Element | Content (%) |
|---|---|---|---|
| Carbon (C) | ≤ 0.08 | Chromium (Cr) | 18.0 – 21.0 |
| Manganese (Mn) | ≤ 1.50 | Nickel (Ni) | 8.0 – 11.0 |
| Silicon (Si) | ≤ 2.00 | Molybdenum (Mo) | Not specified |
| Phosphorus (P) | ≤ 0.04 | Sulfur (S) | ≤ 0.04 |
Typical wrought reference: AISI 304. As-cast microstructure contains 10–25% delta ferrite, giving the part a slight magnetic response.
Mechanical Properties (Annealed)
| Property | Value | Unit |
|---|---|---|
| Tensile Strength | ≥ 485 (70) | MPa (ksi) |
| Yield Strength (0.2% offset) | ≥ 205 (30) | MPa (ksi) |
| Elongation | ≥ 35 | % |
| Brinell Hardness (typical) | 140 – 200 | HBW |
| Solution Annealing | ≥ 1040°C, water quench | — |
| Service Temperature Range | −196 to +400 | °C |
Mechanical certificates (EN 10204 3.1) issued per batch upon request.
Dimensional Precision & Surface Finish
What you can expect from our 304SS investment castings — verified with CMM reports on every order.
| Feature | Capability | Note |
|---|---|---|
| Linear Tolerance | ±0.5% of nominal (min. ±0.10 mm) | Per VDG P690 / CT7-CT9 |
| Surface Roughness (as-cast) | Ra 3.2 – 6.3 μm | After shot blasting |
| Flatness / Straightness | 0.15 mm / 100 mm | Sealing faces machined if required |
| Wall Thickness Min. | 2.0 mm (typical) | Down to 1.5 mm for small parts |
| Finish Options | As-cast, blasted, pickled & passivated, electropolished, CNC machined | Per drawing |
Dimensions verified with calibrated CMM; reports included with shipment.
The Investment Casting Process at Leesh
One in-house lost-wax chain — eight controlled stations between your drawing and the dispatch dock.
Tooling & Wax
Aluminum or P20 steel dies; wax injection with controlled cooling for stable dimensions.
Tree Assembly
Wax patterns gated onto runners — gate position engineered for balanced filling.
Ceramic Shell
Six to eight slurry + stucco coats build a shell that holds the exact cavity shape.
Dewax & Fire
Steam autoclave removes wax; shell fired at high temperature for strength.
Melting & Pour
304SS melted under spectro control, poured into preheated shells.
Cut-off & Clean
Shell knocked out, runners cut, gates ground and parts shot blasted.
Annealing & Machining
Solution anneal restores corrosion resistance; CNC finishing to print.
Inspect & Ship
Dimensional, pressure and material checks before crating.
Foundry Inside
Step inside Leesh Holdings — wax injection, shell building, melting and machining under one roof.
Wax Injection
Shell Building
Melting & Pouring
Machining & CMMWhere These Castings Are Used
304SS investment castings earn their place wherever corrosion resistance meets complex geometry.
Quality Control at Every Station
- Spectrometer verification of each melt before pouring
- Tensile test coupons per heat with EN 10204 3.1 certificates
- CMM dimensional inspection on first article and per batch
- X-ray and dye penetrant inspection available on critical parts
- Hydrostatic and air pressure testing for pressure-rated components
- Passivation per ASTM A380 after machining
- Ferrite content check where weldability matters
- Packaging engineered for ocean freight protection
Planning a 304SS Investment Casting?
Send your drawing — we will respond with tooling cost, piece price and delivery schedule within 24 hours.
david.lee@leesh.cn
