Inspection That Happens Before the Parts Ship
A dimensional report is only useful if it measures the features your assembly depends on. We agree those features at DFM, measure them at first article and at the end of the lot, and send the numbers with the parts.
Measure the feature the assembly uses
Most quality disputes are not about whether a part is good — they are about whether it was measured the way it will be used.
A bore measured in free state is not the bore that receives a hinge pin under load. A flatness callout checked on a surface plate says nothing about what happens when four screws pull the lid down. Where a dimension is assembly-critical, we ask how the part is used and agree the measurement method before the first lot.
We also tell you what we cannot measure. If a callout needs equipment we do not run, you hear it at DFM — not in a report that quietly omits the line.
What we hold
- ±0.01 mm on machined features
- ±0.05 mm profile section and local wall
- ≤ 0.30 mm/m straightness, ≤ 0.50 mm/m twist
- 0.3 mm minimum wall, proven by measurement not by claim
- First article and final inspection on every lot
Our Internal Standard Is Tighter Than the National Standard
Extruded aluminum profiles are covered by GB/T 5237.1. We wrote our own internal control standard for 3C-grade high-precision profiles and set every dimensional limit below the high-precision grade of the national standard. The comparison is published here rather than summarised in a brochure sentence.
| Inspection item | Spec range | FandorAlu internal standard | GB/T 5237.1 high-precision |
|---|---|---|---|
| Profile section dimension (main functional surfaces) | ≤ 50.00 mm | ±0.05 mm | ±0.15 mm |
| Local wall thickness tolerance | 0.80–3.00 mm | ±0.05 mm | ±0.10 mm |
| Straightness (per metre) | Full length | ≤ 0.30 mm | ≤ 0.50 mm |
| Twist (per metre) | Full length | ≤ 0.50 mm | ≤ 1.20 mm |
Inspection uses 0.001 mm digital micrometers and precision plug gauges for routine sampling; critical structural features are verified on a coordinate measuring machine (CMM) across the full measuring range.
The standard is documented as Q/FD 001-2026, issued 2026-05-09 and effective 2026-05-10, drafted by the FandorAlu technical department.
What this standard covers — and what it does not
- It covers extruded aluminum profiles: section dimensions, local wall thickness, straightness and twist
- It does not describe CNC machining limits — machined features are specified per drawing, at ±0.01 mm where the assembly needs it
- It is an internal control document, not a certificate, and it is not a substitute for your own incoming inspection
- If your qualification process needs the document itself, ask and we will send it with the quotation
Profile is checked at the press exit, not only after ageing — a section that measures at the die can still bow over three metres.
Every die on this wall is a section we control: the tolerance in the table above starts at die design, not at inspection.
Three checkpoints between drawing and shipment
Each checkpoint produces something you can read, not a verbal assurance.
First article inspection
Every critical feature on the drawing is measured and recorded on the first part of the run. The report ships with the sample so approval is based on numbers. If a feature needs a die or fixture correction, this is where it is caught.
In-process checks during machining
Wall thickness and bore size are checked during the run, after stress relief, not only at the end. A 0.3 mm wall that moves mid-lot is a fixture problem, and it is cheaper to find it at part 50 than at part 5,000.
Final inspection and appearance sign-off
Dimensional check on the finished lot, then appearance against the approved sample and retained colour chip under consistent light. Threads are gauged, sealing faces checked, and packaging inspected before the carton closes.
Paperwork in the box
| Document | When | What it covers |
|---|---|---|
| DFM note | Before tooling | Wall, draft, tolerance stack, finish and process route |
| First article report | With the sample | Critical features measured against the drawing |
| Lot inspection record | With the shipment | Final dimensional and appearance result |
| Colour chip | Before production | Retained reference for every subsequent lot |
| Packing list | With the shipment | Quantity, carton count, gross weight |
Need a specific inspection format for your supplier portal? Send the template with the drawing and we will fill it rather than inventing our own.
Non-conformance, handled plainly
- We tell you first. If a lot is out of tolerance, you hear it before the carton ships, with the measurement and the proposed disposition.
- We separate cause from blame. A drawing change, a die correction and a machining error are three different problems with three different fixes.
- We fix the process, not the report. Reworking a lot solves one shipment; correcting the fixture solves the programme.
- We do not ship and hope. A part that fails appearance is held even when it passes dimensions.
On certification: we publish ISO 9001:2015 for our quality management system, and nothing else. Serving an industry does not imply certification for that industry, and we do not hold CE, RoHS, UL, ISO 13485 or IATF 16949. If your qualification process needs specific certificates, ask us and we will confirm in writing exactly what we hold.
Quality questions procurement teams ask
The questions that come up in every supplier audit call.
How does Q/FD 001-2026 compare with GB/T 5237.1?
On section tolerance up to 50 mm, ±0.05 mm against ±0.15 mm. On local wall thickness over the nominal 0.80–3.00 mm range, ±0.05 mm against ±0.10 mm. Straightness is 0.30 mm per metre against 0.50 mm, and twist is 0.50 mm per metre against 1.20 mm. The second figure in each pair is the GB/T 5237.1 high-precision grade.
Does Q/FD 001-2026 cover CNC machined features?
No. It covers extruded profile dimensions only. Machined features are held to ±0.01 mm and documented separately, so do not apply the profile figures to a machined bore or face.
Can I get an inspection report with the first sample?
Yes — it is standard, not an extra. The report covers the critical features on your drawing, measured after stress relief and before finishing where the anodic layer would affect the reading.
Do you use a CMM?
Yes. Routine sampling runs on 0.001 mm digital micrometers and precision plug gauges, and critical structural features are verified on a coordinate measuring machine across the full measuring range. If a drawing callout needs equipment we do not run, you hear it at DFM rather than finding a missing line in the report.
How is appearance judged?
Against the approved sample and the retained colour chip, under consistent light. Texture matters as much as colour on a bead-blasted part, so both are approved physically before production.
Ask for the Report Before You Place the Order
Send the drawing and tell us which features your assembly depends on. We will confirm what the first article report will cover.
What to send
- 2D drawing or 3D model (STEP, IGES, DWG, DXF, PDF)
- Alloy and temper
- Surface finish and color
- Estimated annual quantity