01
Dimensions drift across the run
First articles pass, then part 300 is out of tolerance. Tool wear and thermal growth were never tracked between first article and full production. You find out at assembly, when the fixture no longer closes.
Quality Control
Our CNC Quality Control System
A QC system only matters if it catches problems before parts ship. GreatLight inspects raw material, monitors cutting in process, and checks 100% of parts before dispatch, with reports on request.
±0.005 mm tolerance100% inspectionISO 9001:2015IATF 16949:2016Reports on request
99.99%Qualification rate
±0.005 mmRepeatable tolerance
127High-precision CNC machines
15 yearsMachining since 2011
Where it goes wrong
Do any of these sound familiar?
Most quality failures show up at assembly, not at the machine. Here is what we hear from engineers.
02
No inspection record for the shipment
Parts arrive without a dimensional report, material certificate or finish reading. Your own incoming inspection has to be built from scratch, and a rejected lot has no traceable cause.
03
Surface finish called out but not measured
A drawing says Ra 0.8 μm and the parts look fine under shop light. Without a profilometer reading, the seal face or sliding surface fails leak testing after anodizing.
04
Supplier changes the process quietly
A different tool path, a different heat treat lot, or a switched material grade. Nothing is documented, so the change only surfaces when the customer's own line starts rejecting parts.
How we control it
Inspection at three points, not one
A QC system has to be built into the process, not bolted on at the end.
Incoming and in-process
Material check first, then monitoring while cutting
Every incoming bar, plate and billet gets a material certificate check before it goes to a machine. Grade, heat number and condition are matched against the drawing. If a certificate does not line up, the lot does not enter production.
On the floor, operators check critical dimensions at set intervals through the run. When a feature is tight, we check more often. The first article is measured and approved before the rest of the batch runs, so a tooling error is caught on one part instead of three hundred.
- 1Material traceabilityCertificates matched to grade, heat and condition before release to machining.
- 2First article approvalCritical features measured and signed off before the batch continues.
- 3In-process intervalsShort-interval checks on tight features; longer intervals on open tolerances.
Final inspection
100% inspection before anything ships
No sampling on the final gate. Every part is inspected before it is packed. That covers dimensions on the drawing, thread gauging, surface finish where it is specified, and visual checks for burrs, tool marks and handling damage.
Where a drawing calls for it, we measure finish with a profilometer and record the reading. Laser-marked parts are checked for character height, since anything under 1.5 mm tends to read poorly after anodizing. Reports ship with the parts when you ask for them.
- 1Dimensional and thread checksDrawing dimensions and gauged threads across the full lot.
- 2Finish measurementProfilometer readings when a Ra value is specified on the print.
- 3Documented resultsInspection reports and material certificates provided on request.
Stage by stage
What gets checked and when
| Stage | What we check | Output |
|---|---|---|
| Incoming material | Grade, heat number, condition, cert | Material certificate on file |
| First article | Critical dimensions, datum setup | Signed first article record |
| In-process | Trend dimensions at set intervals | Operator check sheets |
| Final | 100% dimensions, threads, finish, visuals | Inspection report on request |
| Before packing | Count, burrs, handling marks | Packed and labeled lot |
Where the system applies
Services covered by the same QC flow
The inspection path follows the part, whatever process makes it.
01
5 Axis CNC Machining
16 simultaneous 5-axis centers handle contoured and angled features in one setup, which cuts the number of datum shifts that can introduce error.
02
CNC Milling & Turning
27 three-axis machines and 16 mill-turn centers cover prismatic and round parts, with the same first-article and in-process checks.
03
Rapid Prototyping
One-off and low-volume parts get measured against the model before shipment, so a prototype is not a guess about fit.
04
Sheet Metal Fabrication
Bend angles, hole positions and flatness are checked after forming, where springback is the usual source of rejection.
05
Part Surface Finishing
Anodizing, plating, powder coating and bead blasting are inspected after the finish, not before, since the coating changes dimensions.
06
Custom 3D Printing
Printed parts are checked for critical dimensions and layer defects where the part carries a fit or a seal.
Capability limits
What the system can hold
| Item | Range | Notes |
|---|---|---|
| Tolerance | ±0.005 mm | Typical on turned and milled features |
| Fine finish | Ra 0.2–0.8 μm | Measured with a profilometer |
| Standard finish | Ra 0.8–1.6 μm | Common on mating surfaces |
| As-machined | Ra 1.6–3.2 μm | Non-critical faces |
| Maximum part size | 4,000 mm | Larger travel on request review |
| Rotary table | Ø400 mm | For round and indexed features |
Why this holds up
Numbers behind the QC system
99.99%
Qualification rate
The share of parts that pass final inspection. It comes from checking at three stages instead of relying on a single end-of-line gate.
±0.005 mm
Repeatable tolerance
Held on turned and milled features with temperature-controlled cutting and short-interval in-process checks.
ISO 9001
Quality management
Documented procedures for inspection, calibration and non-conformance handling, audited under ISO 9001:2015.
IATF 16949
Automotive discipline
Process controls and traceability built for automotive and EV programs, including PPAP-style documentation on request.
ISO 13485
Medical device parts
Cleanliness, traceability and inspection records aligned with medical device manufacturing requirements.
ISO 27001
Design confidentiality
Your drawings and models are handled under an information security management system, with NDA available on request.
150Technicians on staff
7,600 m²Manufacturing space
3Wholly-owned plants
12 hQuote and DFM turnaround
Industry requirements
What each industry needs, and what we deliver
Aerospace brackets
Thin-wall aluminum brackets need flatness held after machining, not just at the machine.
- ±0.005 mm
- First article approved
- Material cert on file
EV and automotive housings
Sealing faces and bore positions drive fit and leak performance on the vehicle line.
- Ra 0.8–1.6 μm
- IATF 16949:2016
- 100% inspection
Medical instrument parts
Small stainless components need clean edges and traceable material lots.
- 316L
- ISO 13485:2016
- Burr-free edges
Robot and automation frames
Mounting patterns and joint faces have to line up across a multi-part assembly.
- Multi-part fixturing
- In-process checks
- Reports on request
FAQs
Questions engineers ask about our QC system
What does your QC system actually check?
Three stages. Incoming material is checked against the certificate and the drawing. During cutting, operators measure critical dimensions at set intervals. Before shipment, every part is inspected for drawing dimensions, threads, specified surface finish and visual defects.
Reports and material certificates are available on request. If you have an incoming inspection format you want us to fill out, send it with the RFQ.
Do you inspect every part or use sampling?
Final inspection is 100% before shipment. Sampling is used only for non-critical visual attributes where the drawing does not carry a tolerance.
For tight features, in-process checks run at short intervals through the batch to catch drift before the part count gets away from us.
How do you hold ±0.005 mm on a production run?
Machine condition, fixturing and thermal control do most of the work. The rest is measurement discipline: first article approved before the run continues, then periodic checks on the same features with the same gauge.
If a feature is tighter than the process can hold reliably, we say so during DFM review rather than promising a number we cannot repeat.
Can you measure and report surface finish?
Yes, when the drawing specifies a Ra value. We measure with a profilometer and record the reading in the inspection report.
Finish is measured after anodizing, plating or coating where those processes are applied, because the coating changes the surface.
What certifications back the QC system?
ISO 9001:2015 for quality management, IATF 16949:2016 for automotive work, ISO 13485:2016 for medical device parts, and ISO 27001:2022 for information security.
Each one sets requirements for documented procedures, calibration records and non-conformance handling, which is what you see in the inspection paperwork.
How do you handle a rejected lot?
The lot is held, the non-conformance is documented, and the cause is traced to the process step. Rework is only done when the drawing allows it and the reworked part is re-inspected.
If parts cannot be brought into specification, we tell you before shipping rather than sending a lot you have to reject at incoming inspection.
Will my drawings stay confidential?
Uploads go through a secure channel, and information is handled under an ISO 27001:2022 management system. An NDA is available on request before you send files.
Access to your models is limited to the people who need it for quoting and machining.
Can I get a first article inspection report with the parts?
Yes. Ask for it when you place the order and specify which dimensions and features you want recorded. We fill out your format if you have one.
For production runs, the first article is measured and approved before the batch continues, so the report reflects the setup that made the parts.
Send a drawing and we will tell you how we would inspect it
Quote and DFM analysis within 12 hours. No minimum order quantity, from one prototype to 10,000+ parts.
12-hour quote100% inspectionNo MOQNDA on request
