We are a lost-wax investment casting foundry in Dongguan, China. We cast stainless, carbon and low-alloy steel, nickel and cobalt alloys into parts that arrive at your machine shop needing a finish pass, not a rescue. Most of what follows is about the parts where that is hard.
What we make, and for whom
Four industries account for most of our work. Each one has a different failure that matters, and that changes how the part is gated.
Marine and pump hardware
Impellers, valve bodies, sea-water fittings. The failure that matters is leakage and pitting, so the shell has to be tight and the alloy has to be the one the drawing actually specifies — not the nearest equivalent.
Automotive and motorcycle
Brackets, housings, exhaust-side components. Volume is high, so the wax die and the cluster layout decide the unit cost more than the melting does.
Medical and instrument
Small, thin, dimensionally tight. Here the tolerance bands and the surface finish are the whole conversation, and a 0.2 mm deviation is a rejected lot.
Industrial machinery
Gears blanks, linkage parts, wear components. Usually heavy sections with isolated thick bosses — the classic shrinkage case.
The process, without the sales language
Wax pattern, ceramic shell, dewax, fire, pour, knock out, finish. Eight steps, and the three that cause most of the trouble are the ones nobody photographs.
- DewaxingThe autoclave pressure ramp. Raise it too fast and the wax boils inside the shell, cracks it from within, and you find out weeks later at the pressure test.
- Shell drying60–70% RH with no air movement on face coats, 40–60% RH with 6–8 m/s air on backup coats. Get this wrong and the layers delaminate quietly.
- DeoxidationThe aluminium addition before tapping. Too much and the impact toughness goes; too little and the oxygen stays in the bath and comes out as porosity.
Start from the material, not the drawing
Most sourcing problems we see are not casting problems. They are a grade substitution that looked harmless on paper: CF8M written where CF3M was needed, a wrought 316 part redrawn as a casting, a Chinese grade designation matched to the nearest American one and assumed identical. The carbon, the ferrite content and the heat treatment all shift, and the drawing does not say so.
We keep two references for this: a guide to alloy selection and cross-standard grade comparison, and a data sheet with tolerance bands, surface finish and mechanical properties per grade.
If you are designing the part
Wall uniformity, fillet radius, draft, and the depth-to-diameter limit on cast holes decide whether the part casts well anywhere, or only at a foundry willing to lose money on it.
If you are costing the part
Piece weight, cluster yield and the alloy addition per heat drive the price. We published the arithmetic so the numbers are arguable instead of magic.
Where the defects come from
Shrinkage porosity, hot tearing, gas porosity, inclusions, dimensional drift. Five failure modes cover almost every rejection we have ever investigated, and each one has a mechanism you can point at rather than a checklist you guess from.
Read the defect reference — symptom, mechanism, correction, and the upstream step that actually caused it.
Recent technical notes
- Troubleshooting shell cracking: dewaxing versus firingA crack that appears after firing is rarely a firing problem. How to tell the two apart from the crack path.
- Shell leakage in narrow slotsWhy slurry bridges across a 2 mm slot and what actually clears it.
- Pitting defects: causes and mechanismsPitting is a surface chemistry problem before it is a casting problem.
Send a model and a quantity
STEP file, the critical dimensions marked on a 2D drawing, annual quantity and expected batch size. That is enough for a real number rather than a range. If the part has a pressure-tightness requirement, say so at this stage — it changes the gating design and sometimes the alloy.
About the company
Dongguan Xinyouyuan Hardware Products Co., Ltd. has been casting precision components since the workshop era of the business, and now runs silica sol shell lines with in-house wax injection, shell building, medium-frequency melting, heat treatment and dimensional inspection. We also publish two free references for the trade: a practical ProCAST simulation handbook and an atlas of investment casting defects.