CNC Machining Cost in China: What Actually Drives the Price Per Part
Published 28 October 2026 · 9 min read
Send one drawing to five suppliers and you can receive five prices that differ by a factor of three. The spread is rarely about greed. It usually means the suppliers are quoting different processes, different batch assumptions, or different levels of documentation — and the buyer only sees the bottom line.
This piece breaks a CNC quote into the five blocks that make it up, explains why identical drawings produce different numbers, and shows where buyers pay for things they never asked for.
The five cost blocks in every quote
Every honest CNC quotation is built from the same five pieces. Once you know the structure, you can compare quotes line by line instead of comparing totals.
| Cost block | Typical share | What moves it |
|---|---|---|
| Material | 20–45% | Alloy grade, stock size vs finished size, whether the supplier buys retail or mill-direct |
| Programming & setup | 10–25% | Number of setups, fixturing complexity, whether CAM work is amortised over a large batch |
| Machine time | 25–45% | Material removal volume, tolerance class, surface finish requirement, machine type |
| Finishing | 5–20% | Anodising, passivation, plating, powder coating — often outsourced, often marked up |
| Inspection & docs | 3–10% | FAI report, CMM programme, material certs, PPAP-level documentation |
The ranges are wide on purpose. A simple aluminium bracket may sit at the low end of every block; a titanium medical housing with a ±0.01mm bore sits at the high end of all five.
Why the same drawing gets quotes three times apart
1. Machine selection
A part with features on four faces can be made on a 3-axis mill in four setups, or on a 5-axis machine in one. The 3-axis route has more labour and more accumulated error; the 5-axis route has a higher hourly rate but fewer hours. A supplier quoting the 3-axis route may come in cheaper on a single piece and more expensive on a thousand, because setup stops mattering and cycle time doesn't.
2. Batch assumption
When a drawing doesn't state quantity, suppliers guess. One assumes 10 pieces, another assumes 500. The 500-piece quote can look dramatically cheaper per unit even though the per-hour rate is identical. Always compare quotes at the quantity you actually intend to order.
3. Stock strategy
Machining a 60×60mm part from 70mm bar wastes material but requires no special order. Ordering near-net-size stock saves material but adds lead time and a minimum order quantity. Two suppliers can legitimately reach different answers here, and both can be right.
4. Hidden finishing and freight
Anodising is frequently subcontracted. Some quotes include it, some exclude it, some include it but exclude the extra handling and re-packing that comes with sending parts out and getting them back. Ask explicitly whether the number is ex-works, FOB, or delivered.
Where buyers pay for things they never asked for
Over-tight tolerances. A ±0.1mm callout that could have been ±0.2mm can add 20–40% to cycle time, because the machinist must slow down, take lighter cuts, and measure in-process instead of at the end.
Unnecessary surface finish. Specifying Ra 0.4 on a face that bolts against a rubber gasket buys nothing but a second operation.
Overspecified material. 7075-T6 where 6061-T6 would do can double material cost; the strength is rarely the limiting factor in a bracket.
General tolerance blocks left at default. A title-block note of ±0.05mm applied to every dimension forces precision on features that don't need it.
How to cut cost without cutting quality
- Reserve tight tolerances for the two or three dimensions that actually function. Note the rest as general tolerance.
- Give the supplier your real annual volume, not just the first order. It changes their stock and fixturing decisions.
- Ask for a DFM review before quoting. Moving one hole 2mm can remove an entire setup.
- Accept a standard stock thickness where the design allows it. Custom thickness means custom material order.
- Compare quotes at identical Incoterms and identical finishing scope. Half of all "cheaper" quotes are simply quoting less.
What a fair quote should contain
A quote you can actually compare should state: unit price at your quantity, material grade and stock form, tolerance class assumed, finishing included or excluded, inspection documentation included or excluded, lead time from PO and from drawing approval, Incoterm, and payment terms. If two or three of those are missing, the number is not comparable yet.
At our precision CNC machining operation we quote within 24 hours on a drawing or STEP file, and the quote states each of those items so you can put it side by side with anyone else's.
Frequently asked
Is a lower price per part always a worse supplier?
No. A supplier with the right machine already set up for similar work can genuinely be cheaper. The warning sign is a low price with an unclear scope — no stated tolerance class, no stated finishing, no stated Incoterm.
How much does quantity reduce unit price?
Most of the drop happens between 1 and 50 pieces, where programming and fixturing get amortised. From 500 to 5,000 the curve flattens considerably, because machine time dominates and it doesn't shrink with volume.
Should I send a STEP file or a 2D drawing?
Send both. The STEP file defines geometry unambiguously; the drawing carries tolerances, surface finish, material and thread callouts that a 3D model cannot express.
Does tooling cost apply to CNC machining?
Not in the injection-moulding sense. There is no mould to cut. You may see a one-off programming or fixturing charge on complex parts, but it is charged once, not per unit.
Send a drawing, get a costed quote in 24 hours
Tolerance class, finishing, inspection scope and lead time stated line by line, so you can compare it against any other supplier.
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