Choosing a CNC contract manufacturer abroad is not a one-off price comparison; it is a decision about a business relationship that will last several years. The right questions give you information from the supplier's daily operations rather than from the glossy photos in its presentation. The 15 questions below are a practical checklist that purchasing and quality teams can use at the RFQ stage or during a supplier visit.
A. Technical Capability
1. What is your machine park, and on which machine will my part be produced?
Ask for brand, model, number of axes and age. A good answer explains on which machine and in how many set-ups your part will be produced. A vague "we can do anything" is a warning sign. We list Tornelle's machine park openly on our About Us page.
2. What inspection equipment do you have?
Is there a CMM, are the calibration certificates up to date, how are surface roughness and threads measured? If your tolerance is ±0.01 mm, a supplier that checks with callipers is not sufficient.
3. Which materials do you work with regularly?
Stainless steel, aluminium, brass and free-machining steel are standard; ask about real experience with materials such as titanium, Inconel or PEEK. "We can" and "we do it every month" are different things.
4. How are surface treatments and heat treatment managed?
Anodising, plating and hardening are mostly done by external suppliers. Ask: is there an approved sub-supplier list, how is it included in the schedule, is measurement carried out after coating?
B. Quality System
5. Is your quality system certified, and how does it work?
ISO 9001 is a good start; but rather than the certificate, ask how the control plan, first article approval and non-conformance management operate. Request a sample inspection report and a non-conformance record. See our quality assurance article for details.
6. How is material traceability ensured?
Is the heat number written on the work order, is the EN 10204 3.1 certificate matched to the batch? Our material certificate guide explains what to expect.
7. What is the process if defective parts occur?
A good answer includes the notification period, root cause analysis (8D or similar), the remanufacturing/credit policy and responsibility for shipping. Write these into the quality agreement.
C. Capacity and Delivery
8. What is your current utilisation and your typical lead time?
A fully booked workshop cannot promise 2-week delivery. A realistic answer describes 2–5 weeks depending on part type and reserved capacity for customers with an annual call-off schedule.
9. Do you have the capacity for my annual volume, and how is growth managed?
A supplier that allocates more than 30% of its capacity to a single customer is a risk both for you and for itself. Ask about shift and machine investment plans.
10. What is your on-time delivery performance?
A supplier that measures and reports its OTD (on-time delivery) rate is more reliable than one that does not. Ask reference customers for confirmation.
D. Commercial Terms
11. What does the price include?
Are the delivery term (FCA/DAP), packaging, inspection report, certificate and set-up cost included in the price? Compare quotes on equal terms; our Incoterms guide will help.
12. Payment terms and currency?
Advance or partial advance payment is normal for the first order; once the relationship is established, 30–60 days is common. Euro/USD-based pricing and who carries the currency risk should be clear.
13. How are prices updated?
A transparent, raw-material-indexed update once or twice a year is healthy. Planning is difficult with a supplier that requotes on every order.
E. Communication and Risk
14. Who is my technical contact, in which language, and how quickly will I get a reply?
Ask for an engineer who can answer technical questions as your contact, not a sales representative. A reply within 24 hours should be standard.
15. How are my drawings and know-how protected?
Do they sign an NDA, where are the files stored, what is shared with sub-suppliers? Expect a concrete answer.
How to Evaluate
Score each question from 1 to 5 and weight technical capability and quality at 50%, capacity and delivery at 25%, and commercial terms and communication at 25%. Then place the same sample order with 2–3 candidate suppliers and compare the inspection report, lead time and communication quality in practice. A sample order says more than a ten-page presentation. To understand how the price is built up, our article on the 12 factors will help.
Frequently Asked Questions
Is it essential to visit the supplier?
Not for the first order; a sample order and a video factory tour cover most of the risk. A visit is recommended once the annual volume grows.
Is a supplier without ISO 9001 certification ruled out?
In automotive and medical, mostly yes. In other sectors it makes more sense to look at a working quality system (control plan, inspection report, traceability) rather than the certificate.
How many suppliers should I work with?
At least two approved sources are recommended for critical parts; however, splitting the volume raises the unit price. The common model is a main supplier plus an approved back-up supplier.
What is the most common risk with Turkish suppliers?
Delivery delays due to full capacity. This risk is managed by sharing a call-off schedule and by a capacity reservation agreement.
Conclusion
The right CNC contract manufacturer is the one that gives concrete answers on machine park, inspection equipment, traceability, capacity and communication, and keeps its word on the sample order. You are welcome to ask us these 15 questions too: send your technical drawings via our quote form and we will send the answers together with the quote.
