Quality control here is a fixed sequence: four inspection stages, an independent laboratory test on every bulk batch, and one rule that decides the outcome — if a batch does not match the material we quoted, it does not ship. Below is what is checked at each stage, what happens when something fails, and which figures we confirm per model rather than publish.
The four inspection stages
1. Incoming material
Material is checked against the grade we quoted before it is released to production — stainless steel 304, 316 or 201, zinc alloy or brass. A lot that does not match the quoted grade is not put into production.
2. In production
Parts are checked during the run, not only at the end, and sampling is stratified by model — a mixed order is inspected model by model, not as one lump. A model that fails is held back and is not released until it passes.
3. Bulk retained sample
A sample is drawn from each bulk batch and kept on file. If a question comes up months later, the retained sample is what the shipped material is compared against.
4. Before shipment
The final check runs against the confirmed order: models, quantities, finishes and packing, before the goods are loaded. No batch is released without passing inspection.
While your order runs
Inspection is not a single event at the end of production. While an order is running we ask the workshop for a progress report and work-in-progress photographs every 3–5 days, so you see the parts taking shape instead of waiting for the container. A problem visible at that stage can still be corrected in the run.
Nothing is released on schedule alone: no batch is released without passing inspection, whatever the loading date says.
Independent laboratory analysis and retained samples
In-house checks cannot prove what a material actually contains, so we do not rely on them for that. Every bulk batch is sampled for spectrometer analysis at an independent laboratory. The result tells us the composition of the steel, zinc alloy or brass in that batch — not what a supplier declared on a delivery note.
Spectrometer results are kept on file for every batch, and retained samples are kept alongside them. If you ask whether a shipment is really 304 or 316, that is the evidence the question is answered with.
What a material certificate means
A material certificate is a statement of composition — what the metal in the batch is made of. It is not a management-system certificate, not a product-conformity mark such as CE, and not a third-party test report. Buyers often treat these as one document; they are issued by different parties and answer different questions.
Where you need a material certificate or an inspection report, we can issue it to your own template on request, drawn from the batch records above. Compliance & documents sets out each kind of certificate and who issues it.
Routine in-house testing
Routine in-house testing covers salt spray, pull and service-life. These are run as routine checks on finishes and fittings, not as published benchmarks: we do not quote test durations, test standards or pass figures here, because the meaningful figure depends on the model, the material and the finish.
If you need the figure that applies to a specific model — for your own specification sheet or for a tender — ask for that model and we confirm it against the batch record. The same applies to rated load figures for hinges and rollers: confirmed per model, never as one number for a product line.
The boundary is simple: a batch that does not match the material we quoted does not ship, and inspection results are confirmed per model rather than published as a general figure. If a batch does reach you with a fault, after-sales explains what to send and what happens next.