When you buy a machining center from overseas, the factory acceptance test is the single most important checkpoint before money and freight commit you. Done properly, a FAT lets you accept the machine on documented evidence — not trust. This guide covers exactly what a CNC FAT should test, what a signed protocol must contain, and how to run one in person or by live video.
What is a factory acceptance test (FAT)? A factory acceptance test is a structured verification of a CNC machine at the manufacturer's plant, before shipment. It confirms the machine meets its agreed specification — geometric and positioning accuracy to VDI 3441, repeatability, spindle and axis function, and control operation — and ideally includes a sample part machined to your drawing. Every result is compared to the spec and recorded in a signed FAT protocol, so you accept the machine on evidence you can hold the supplier to. This is the supporting deep-dive to our guide on importing a CNC machine from China safely.
A problem found during a FAT is the supplier's to fix, on their floor, before the machine is crated. The same problem found after a sea voyage and customs is slow, expensive and disputed. A FAT moves the risk to where it is cheapest to resolve — and ties your final payment to a result, not a promise.
Tie the balance payment (or release of retention) to a passed FAT. Verification and money move together, which aligns both sides on getting the machine right.
A signed protocol with measured values converts "it meets spec" into a document. If anything drifts in transit, you have a baseline to compare against on arrival.
Knowing the machine passed at the plant makes on-site installation and commissioning faster — you are confirming a known-good machine, not discovering it.
Agree the scope in writing before the test. A thorough CNC FAT covers:
The protocol is what you keep. It should record, for each item: the agreed specification, the measured value, the instrument used, pass/fail, and any deviation with its agreed resolution. Add the machine serial number, the date, and the names and signatures of both the manufacturer's and the buyer's representatives. Attach the VDI 3441 measurement records and the sample-part inspection report. A protocol like this is the baseline you re-check against once the machine arrives and is commissioned on site.
Do I have to travel for the FAT, or can it be remote? Both work. An in-person FAT lets your engineer witness the tests and inspect the sample part directly. A remote (live-video) FAT has the manufacturer run the agreed protocol on camera, show the measurement records live and share the sample-part inspection report — letting overseas buyers verify a machine against spec without the travel cost and lead time. HALLERBS supports both; the key is that the protocol and evidence are the same either way.
Quality is built in during the process, then confirmed at FAT — not inspected in at the end.
After a passed FAT comes on-site installation & commissioning — where accuracy is re-verified after transit (the SAT) — then training, genuine spares and remote diagnostics; see also Quality & Certifications.
What should a CNC FAT test? Geometric accuracy; positioning accuracy and repeatability to VDI 3441; spindle run-out and thermal behaviour; axis travel, rapids and acceleration; tool-change and magazine function; control and safety operation; and a machined sample part inspected against the drawing — each compared to the agreed spec and recorded in a signed protocol.
Can a FAT be done remotely? Yes — by live video, with the manufacturer running the protocol on camera and sharing the measurement records and sample-part inspection report. HALLERBS supports in-person and remote FATs; the evidence package is the same.
What is the difference between FAT and SAT? A FAT (factory acceptance test) verifies the machine at the manufacturer's plant before shipment; an SAT (site acceptance test) re-verifies it after installation and commissioning at your site. The FAT protocol is the baseline the SAT confirms the machine still meets after transit.
Should payment be tied to the FAT? Yes. Tying the balance payment or retention release to a passed FAT aligns both sides and protects you — verification and money move together rather than on trust alone.
Send your part drawing and target spec. We'll propose a FAT protocol — accuracy to VDI 3441, a sample part to your drawing, witnessed in person or by live video — and a quotation.
