How much does investment casting cost per kg? That question lands on every procurement engineer’s desk—before RFQs, during budget reviews, and especially when comparing offshore suppliers. At QINGDAO QIANGSENYUAN TECHNOLOGY CO., LTD., we’ve quoted over 1,200 investment casting projects since 2018. We’ve seen quotes swing from $8.50 to $47/kg—and not because of markup games. The variance comes from four concrete factors: alloy type, part complexity, batch size, and finishing requirements. This guide cuts through the noise. It gives you a factory-level pricing framework—not theoretical ranges, but what actually moves the needle in real production runs.
Alloy Choice Is the #1 Cost Driver—Not Geometry
Many engineers assume intricate shapes raise investment casting cost per kg most. Wrong. Alloy dominates. Here’s what we see daily:
- Cobalt-nickel alloys (AMS 5387, T800) average $32–$47/kg — driven by raw material volatility, strict melt control, and post-cast heat treatment to stabilize gamma prime phases
- Stainless steels (CF8M, CF3M) land at $18–$26/kg — higher than carbon steel due to chromium/nickel content and tighter chemistry windows
- Ductile iron (ASTM A) holds steady at $9.50–$13.50/kg — low melting point, minimal shrinkage, forgiving shell system
We once quoted a hydraulic pump housing in T800 cobalt alloy at $41.20/kg. The same geometry in ASTM A351 CF8M dropped to $22.60/kg. No design change. Just metallurgy. If your spec allows material substitution—even with minor tensile tradeoffs—you gain immediate leverage on investment casting cost per kg factory pricing.
Complexity Matters—But Only After Critical Dimensions Are Locked
“Complex” doesn’t mean “expensive”—unless it forces manual labor. Investment casting excels at organic shapes, internal passages, and thin walls. What adds cost isn’t curvature or contour—it’s features that break automation: undercuts requiring hand-wax assembly, blind holes deeper than 8× diameter, or surface finishes finer than Ra 1.6 µm without machining.
In one recent order for piston pump cylinder housings, the customer specified ±0.05 mm wall thickness tolerance across a 220 mm ID. That triggered full CMM scanning on every lot—and a 14% premium over standard ±0.15 mm. But when they relaxed tolerance to ±0.10 mm on non-sealing surfaces, cost dropped $2.30/kg with zero functional impact. Our rule: define critical datums first. Then let casting handle the rest.
Volume Changes Everything—Especially Below 500 Pieces
Investment casting cost per kg factory drops sharply between 1–50 pieces and 500–2,000 pieces—but plateaus after that. Why? Tooling amortization. Wax pattern tooling for a medium-complexity part runs $2,800–$4,500. At 50 pcs, that’s $56–$90 added per unit. At 1,000 pcs? Just $2.80–$4.50.
We track this precisely. For a stainless steel pressure valve body (1.8 kg/unit), our quoted investment casting cost per kg factory was:
- $28.40/kg at 50 pcs (includes full tooling + 3-shell iterations)
- $21.90/kg at 500 pcs (tooling fully amortized, optimized shell drying cycle)
- $20.30/kg at 2,000 pcs (batch furnace loading optimized, scrap rate down to 2.1%)
No magic. Just physics, process control, and repeatable setups.
Finishing Isn’t Optional—It’s Priced Per Surface, Not Per Part
“As-cast” is rare in industrial applications. Most customers need at least vibratory deburring and shot blasting. But each additional step compounds cost linearly:
- Vibratory deburr + alumina blast: +$0.85/kg
- Electropolish (Ra ≤ 0.4 µm): +$4.20/kg
- Passivation (ASTM A967 Nitric): +$1.10/kg
- Dimensional grinding of sealing faces: +$6.90/kg (measured per face, not per part)
We recently reworked a cobalt alloy nozzle order where the client requested electropolish *and* localized grinding on two small orifice seats. The finishing alone added $11.30/kg—more than the base casting cost for that alloy grade. Lesson: specify only what seals, slides, or mates. Skip cosmetic finishes unless corrosion resistance or flow calibration demands them.
Getting Real Pricing Starts With Your Drawing—Not Your Budget
Generic quotes are useless. True investment casting cost per kg factory pricing requires GD&T callouts, material certs (AMS, ASTM, EN), and finish notes—not just “stainless steel, good surface.” At QINGDAO QIANGSENYUAN TECHNOLOGY, our quoting team reviews every drawing for manufacturability before quoting. We flag risks: thermal distortion in long thin arms, shell cracking in sharp internal radii, or wax ejection issues in deep pockets. That review takes 48 hours—and saves weeks later.
If you’re evaluating suppliers, ask for their typical scrap rate on your alloy class, their shell system dwell times, and whether they own their ceramic slurry lab. Those details predict consistency better than any price sheet. And remember: the lowest quote often hides rework costs, inspection delays, or dimensional drift across batches.
For accurate, actionable investment casting cost per kg factory estimates—grounded in actual process data, not spreadsheets—start with a validated drawing and certified material spec. The rest follows.
