Who this helps: Design Engineers and Buyers comparing suppliers or choosing between processes (green sand, resin sand, shell) for iron castings (tooling cost vs piece price).
What you’ll learn: a simple break-even formula, when higher tooling pays off, and how YB Metal Solution models cost curves to cut total program spend.
Upload your drawing via /rfq, and YBmetal will return a volume-based cost curve for your exact part.
Author: YB Metal Solution Engineering Team (hereafter YB Metal)
Table of contents
- Why break-even matters
- The break-even formula (copy this)
- Worked example (supplier A vs B)
- Process choice affects break-even
- Practical waypoints you can plan around
- What really moves the curve (beyond process)
- Quick calculator table you can reuse
- Risk controls for real programs
- What you can expect from YB Metal at RFQ
- FAQs
Why break-even matters
A quote with lower tooling but higher piece price can be cheaper at low volumes—yet far more expensive across the program. The only honest way to pick is to compare total program cost and amortized cost per part at your forecast volumes (including ramp).
Key ideas
- Total Program Cost = Tooling + (Piece Price × Volume) + one-off NRE + logistics.
- Amortized Cost/Part = Piece Price + (Tooling ÷ Volume).
- Break-even volume is where two alternatives have equal amortized cost/part.
The break-even formula
- TTT = tooling investment
- PPP = piece price
- VVV = lifetime volume (or compare at forecast waypoints)
- Amortized cost/part C=P+T/V
Two options A and B are equal when:
PA+TA/V=PB+TB/V⇒V=（PA−PB)/(TB−TA)
Break-even:
V=(25,000−5,000)/(20-16)=5,000 pcs
| Volume (pcs) | A amortized CA=20+5000/VC_A = 20 + 5000/V | B amortized CB=16+25000/VC_B = 16 + 25000/V | Cheaper |
|---|---|---|---|
| 500 | $30.00 | $66.00 | A |
| 1,000 | $25.00 | $41.00 | A |
| 2,500 | $22.00 | $26.00 | A |
| 5,000 | $21.00 | $21.00 | Tie |
| 10,000 | $20.50 | $18.50 | B |
Takeaway: If your realistic lifetime is <5k, choose A; if >5k, choose B.
Process choice affects break-even
Different processes shift both tooling and piece price:
- Green sand: lowest tooling, widest piece-price range; best for prototypes, spares, and small–mid volumes.
- Resin sand: medium tooling; better surface/tolerance on complex geometry; mid volumes.
- Shell molding: highest tooling; thin walls/accuracy; wins at higher volumes and tight Ra/CT targets.
Practical waypoints you can plan around
- Prototype/bridge (≤ 500 pcs total): favor lowest tooling, accept higher piece price.
- Mid-volume (1k–5k): compare green vs resin; invest only if surface/CT yields real machining savings.
- High-volume (≥ 10k): higher tooling (e.g., shell or optimized patterns) usually pays back—if the forecast is credible.
Not sure about your ramp? Ask suppliers for two quotes per option:
(a) Tooling only + piece price and (b) “All-in amortized” per part at 1k/5k/10k. That exposes where they hide tooling in the piece price.
What really moves the curve (beyond process)
- Core count & parting strategy – fewer cores and cleaner parting reduce piece price and tooling maintenance.
- Minimum wall & uniformity – design for even sections to raise yield and cut porosity rework. See Wall Thickness Rules .
- Tolerances & machining stock – relax ISO 8062 CT bands where function allows; trim stock on large faces. See ISO 8062 CT grades .
- Surface targets – specify Ra by zone; cosmetic faces cost more than functional faces.
- Tooling life plan – align pattern class to expected 10k/50k/100k moulds; see Pattern Life & Maintenance .
- Supply chain costs – energy, metal, labor and sand shift the piece price baseline; see 2025 Iron Casting Price Drivers .
Quick calculator table you can reuse
| Parameter | Option A | Option B |
|---|---|---|
| Tooling TT | $________ | $________ |
| Piece price PP | $________ | $________ |
| Volume VV | ________ | same |
| Amortized cost/part C=P+T/VC = P + T/V | $________ | $________ |
Risk controls for real programs
- Uncertain volume: negotiate step-down prices tied to cumulative volume.
- Engineering changes: agree ECO rules (what triggers tooling rework; who pays).
- Lead time vs cost: tighter launch dates can force costlier tooling paths; see Lead Times by Process (if published).
- Quality gates: set PPAP level, inspection coverage (CMM/3D scan), and acceptance metrics up front. See PPAP for Iron Castings
What you can expect from YBmetal at RFQ
- A side-by-side break-even model (tooling vs piece price) at 1k/5k/10k volumes.
- A DFM note set to lower core count and machining stock.
- A clearly staged tooling life & maintenance plan aligned to your volume.
- Optional alt quotes (green vs resin vs shell) showing where each wins.
How YBmetal delivers
YB Metal Solution integrates metallurgy, moulding, coating, and inspection under one roof to stabilize surface quality on gray/grey iron, ductile iron, and steel castings:
- Process capability: green sand, resin sand, shell moulding; gating simulation support; prototype to mass production.
- In-house testing: OES spectrometry, tensile/hardness, microstructural analysis, CMM and 3D scanning for surface/DFT/shape verification.
- Quality framework: APQP/PPAP (up to Level 3), FAI, SPC on critical faces, leak/pressure tests upon request.
- Delivery: typical prototype lead time 2–4 weeks; PPAP as agreed per customer program.
- Need help tuning your coating window or building a defect atlas?
FAQs
CTA — specify with proof, not guesses
Build your RFQ with confidence. Upload your drawing and get a break-even analysis from YBmetal that matches your volumes and target launch.