How to Source CNC Parts from China Without Getting Burned
Sourcing machined parts from China is not difficult. Sourcing them in a way that survives an audit, a quality escape and a change of project engineer is. This is the sequence that works, in the order that avoids the expensive mistakes.
1. Write an RFQ that produces comparable quotes
Three suppliers quoting three different scopes is not a comparison. Before sending anything, decide these six things and state them in the RFQ:
- Drawing revision. One revision, clearly named. Suppliers quoting different revisions are quoting different parts.
- Material and condition. Grade, temper, and whether a certificate is required.
- Tolerance intent. Which features are functional and which are general.
- Finish. The process, the specification, and the colour or Ra if it matters.
- Documentation. The exact list of reports and certificates.
- Incoterm and destination. EXW, FOB or delivered, and to which postcode or port.
Add quantity breaks: prototype, pilot, and annual volume. A supplier who quotes only the sample quantity cannot tell you whether the part is economic at production volume, and that is the number your finance team will ask for.
2. Vet the supplier on capability, not on presentation
A website shows machines that may or may not exist and certificates that may or may not be current. Four questions separate the two:
| Question | What a good answer sounds like |
|---|---|
| Which machines will run my part? | Specific models, with axis count and work envelope, matched to your part size |
| How will the critical features be inspected? | Named instruments, plus a statement of what cannot be measured in-house |
| Which certificate numbers do you hold? | Numbers you can verify independently, not just a PDF |
| Who else in my industry do you supply? | A reference you can actually call |
Vague answers to the machine and inspection questions are the clearest signal available. A supplier who cannot say what will measure your part has not thought about how to make it.
3. Compare landed cost, not unit price
Quotes rarely include the same things. Build the comparison on these lines, and insist each supplier prices them:
- Unit price at your real annual quantity
- Tooling, if any, and who owns it
- Finishing and any secondary operations
- Inspection and documentation
- Packaging that survives your warehouse
- Freight, insurance, duty and customs clearance
- Payment terms and the cost of your working capital
A quote 15 percent lower that excludes finishing and inspection is not lower. It is a different scope with a lower headline number.
4. De-risk the first order deliberately
The cheapest insurance is a first article that you measure completely before the batch is released. Structure the first order so this is possible:
- Order the FAI as a separate line item so it has a price and a date.
- Ask for the FAI report before authorising the balance of the batch.
- Measure the first article yourself, on your own equipment, against the drawing.
- Only then release volume, and only if the report and your measurement agree.
If a supplier resists a first article, that resistance is information.
5. The failure modes that actually happen
| Failure | Root cause | Prevention |
|---|---|---|
| Parts measure outside tolerance | Datum scheme on the drawing does not match the setup | Agree the datum and the inspection method before the order |
| Finish does not match the sample | Colour specified by name instead of by standard | Specify RAL or anodising class, and approve a physical sample |
| Second batch differs from the first | Process changed without notification | Require written change notification in the PO terms |
| Paperwork missing at delivery | Documents were not on the PO | List each document by name, with format and delivery method |
| Freight delay eats the buffer | Lead time quoted was production time only | Ask for door-to-door, not ex-works |
6. Make the relationship auditable
Once a supplier is running, three habits keep the relationship from degrading:
- Keep the drawing revision under document control on both sides, and confirm the revision on every PO.
- Track first-pass yield per part number, not overall. Averages hide the part that keeps failing.
- Require notification before any process, material or sub-supplier change. Silent changes are how a good supplier becomes an unpredictable one.
Where we fit
We are a contract manufacturer in Dongguan with 13+ years of experience, a 4,000 m² facility, 300+ production machines, 1,500+ customers and 10 million parts delivered. We hold ISO 9001, ISO 14001 and ISO 13485:2016, and we run eight processes under one roof, which means secondary operations do not get lost between suppliers.
We are not the cheapest quote you will receive, and we will tell you when a part is a poor fit for our equipment. What we will do is state the tolerance we can hold on your critical features, put the documentation in writing, and tell you when we cannot meet a requirement rather than after the parts ship.
Start with one drawing.
Send it through the quote form with your quantity breaks and documentation list. You will get a process route, a tolerance statement on your critical features, and a priced document list, not just a number.
Send your drawing. Get a real quote.
Upload a STEP file and an engineer — not a sales script — replies within 24 hours on working days with price, lead time and DFM notes.