Metal Parts Inspection: FAI, In-Process and Final Checks

By Jessica Cui · Reviewed by Matthew Wu · Last updated 2026-09-28

Metal parts inspection is the paper trail between your drawing and your shipment. Our export company is ISO 9001:2015 certified. TüV Rheinland has verified our factory onsite. The Nanpi factory behind us has produced since 1999. This guide walks the three inspection stages we run. You will see what is measured, when, and what you receive in writing. Use it to check any supplier’s claims, ours included.

The Three Stages

Metal parts inspection is three questions in sequence. FAI asks: is the part right? In-process asks: is it staying right? Final asks: is the box right? Skip one, and one question stays unanswered. That is how a good lot ships with a bad surprise.

First Article Inspection (FAI)

• Every dimension marked on your drawing is measured.
• Material grade is checked against the mill certificate.
• Finish and surface state are photographed from both sides.
• The report lists pass or fail per line, not “all OK”.
• Production starts only after your written approval.

A FAI is a gate, not a favor. If the report shows one fail, we stop and fix before running. Our samples before mass production post covers how the first articles reach you. Some buyers want the physical first article shipped for a fit check. We pack it separately, marked, with its report.

In-Process Checks

• Operators self-check the first pieces of every press hour.
• QC samples at a set interval, logged with time and die number.
• Key dimensions use calibrated calipers and micrometers.
• After any die repair, the first pieces are re-checked.

Sampling catches drift that setup cannot see. A die wears; a bend line shifts 0.1mm over a shift. The log is the proof that the check happened. The full loop is on our quality control during production page. Ask any supplier when they last sampled a run of yours. The answer tells you more than the certificate does.

Final Inspection and Packing

• Final dimensions on a sample from the finished lot.
• Finish check against the approved photo standard.
• Count verified against the order quantity.
• Packing reviewed: orientation, protection, carton marking.
• Photos of the packed line before the container closes.

Packing is part of inspection. A perfect part in a wrong carton is a claim you cannot win. The container photos go in your shipment record. If you receive anything short, the record shows both sides. That setup sits behind our defective parts process, and it usually settles cases before a call.

What You Receive in Writing

• FAI report: every marked dimension, pass or fail.
• In-process sampling log for the run.
• Material certificates from the mill.
• Final measurement report with the lot number.
• Packing photos, container number included.

The material certificate ties the metal to its mill batch. You can read what each line means in our material certificates post. Every document carries the same lot number. That one detail makes an audit traceable in minutes.

Third-Party Inspection

• Available at your cost: SGS, TüV, BV or your house.
• Book it before final inspection, while we can respond.
• We prepare the sample lot and the access list.
• Findings are fixed and re-checked before packing.

A third party is your eyes when you cannot be ours. We welcome it; it is standard on our bigger contracts. If you are still vetting us, the steps are in verifying a sheet metal supplier. An inspection plan agreed before production beats one invented after a delay.

What We Never Do

• We do not start the run without your FAI approval.
• We do not substitute material without your written OK.
• We do not rework a failing dimension and call it in spec.
• We do not hide a miss; the report shows it.

Inspection that hides problems is decoration. Real metal parts inspection forces stops. A stopped line this week is cheaper than a returned container next month.

Frequently Asked Questions

What is an FAI report?

It measures every marked dimension on the first articles. Each line shows pass or fail, with photos and the material certificate reference.

How often do you sample during production?

At a set interval per run, logged with time and die number. The interval is agreed with you on the order sheet.

Can I send my own inspector?

Yes. We prepare the sample lot and access. Third parties like SGS, TüV or BV are standard on bigger contracts.

What happens if a part fails?

We stop, flag the lot and fix the cause. Reworked pieces are re-inspected. The report shows both the miss and the fix.

Are inspection reports included in the price?

Yes, ours are. FAI, sampling log and final report ship with every order, no extra line.

Ship With the Paper Trail

Every order ships with its full inspection records.

WhatsApp: +86 132 1225 5906 | Email: bob@xinjiuxinji.com

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