Vetting a China CNC Supplier: A 10-Point Checklist

By CHX Metal Engineering Team · Published 2026-10-09

A due-diligence checklist for sourcing CNC parts from China - business licence, certifications, in-house vs outsourced, inspection, IP protection, trial orders. Operations are certified to ISO 9001:2015 and ISO 14001:2015, with CMM inspection on every batch.

Choosing a machining supplier overseas is a risk decision as much as a price decision. The checks below are the ones that actually separate a factory from a trading office, and a reliable partner from a one-off seller.

1-3: Identity and legitimacy

1. Legal entity. Ask for the company's full registered name and its Unified Social Credit Code. The name on the invoice, the bank account and the business licence should match. A mismatch is a warning sign.
2. Factory, not just a trading office. Ask for the plant address and, if the order is significant, arrange a video walkthrough or a third-party inspection. A trading office can be a legitimate partner, but you should know which you are dealing with.
3. Equipment list. The machines tell you what the factory can actually make. A shop quoting Swiss-type work should list sliding-headstock lathes; a shop quoting prismatic parts should list machining centres. Vague answers are a warning sign.

4-6: Quality system

4. Certifications, with the certificate number. Ask for the certificate and the issuing body, and check the scope and expiry. A quality system certificate is not a substitute for capability, but the absence of a verifiable one is a real gap.
5. In-house inspection. Ask what is measured, on what instrument, and whether a first-article inspection report ships with the order. A shop with a CMM and a documented inspection routine behaves differently from one that eyeballs parts.
6. Traceability. For regulated products, ask how material and process traceability is recorded. If you need PPAP-style or ISIR documentation, raise it before ordering, because it changes the scope.

At CHX Metal, we hold ISO 9001:2015 (certificate NOA198428, valid to 2028-06-30) and ISO 14001:2015 (certificate NOA2100184, valid to 2027-01-04), issued by NOA, an IAF Multilateral Recognition Arrangement member. IATF 16949 and ISO 13485 are being implemented and are not claimed as held - which is exactly the kind of statement you should be able to get from any supplier.

7-8: Intellectual property

7. NDA and IP policy. A supplier who values your drawings will sign an NDA without fuss. Ask plainly whether your drawings, models and tooling will be used for anyone else, and get the answer in writing.
8. Data handling. Ask how design files are stored and shared internally, who can see them, and whether they are deleted or returned on request after the project ends.

IP protection is a process, not a promise. The right questions are about who has access, how long files are kept, and whether tooling made for you stays yours.

9-10: Commercial terms

9. Lead time and its assumptions. Ask what the quoted lead time includes - is it from order, from material arrival, or from drawing approval? A realistic supplier states the assumptions, not just a number.
10. Communication and escalation. Test it before you commit. How fast is the reply, who answers technical questions, and what happens when a revision comes in mid-project? This is the single best predictor of how the relationship will go.

Red flags worth pausing on

• A price far below the others with no explanation of why.
• Refusal to provide a certificate number, a plant address, or an equipment list.
• Vague answers about inspection or about who machines the parts.
• Hesitation over an NDA, or a claim that one is unnecessary.
• A lead time that does not change whether you order one part or ten thousand.

Run a trial order first

The most economical way to check a supplier is a small trial order rather than a reference letter. Send a part that matters, ask for the first-article inspection data, and measure how the process went from drawing to delivery: how fast was the DFM feedback, was the revision handled cleanly, did the parts match the report. A supplier that passes a trial order is a far safer bet than one that only has a good sales pitch.

At CHX Metal there is no strict MOQ, so a single prototype can be run before a batch is committed. That is deliberate - it lets the working relationship be tested on a small, low-risk order.

Frequently asked questions

How do I verify a China CNC supplier is a real factory?

Ask for the registered company name, the Unified Social Credit Code, the plant address and an equipment list, then confirm the name matches across the licence, the invoice and the bank account. For significant orders, arrange a video walkthrough or third-party inspection.

Should a supplier sign an NDA?

Yes. A supplier who values your drawings will sign one without hesitation. Ask in writing how your files are stored, who can access them, and whether tooling made for you stays yours.

What certification should a CNC supplier have?

ISO 9001:2015 is the baseline quality system certificate. Check the certificate number, the issuing body, the scope and the expiry date. A supplier should say plainly which certificates it holds and which are still in progress.

How do I test a supplier before a big order?

Run a small trial order on a part that matters, and ask for the first-article inspection data. How a supplier handles a real order - DFM feedback, revisions, delivery - tells you more than any reference.

Shenzhen Changhexin Precision Hardware Co., Ltd. (CHX Metal) · Shajing Street, Bao'an District, Shenzhen, Guangdong, China · ISO 9001:2015 (NOA198428) · ISO 14001:2015 (NOA2100184)