Conveyor belt cover thickness failures on China-sourced mining and bulk-handling rubber goods are rarely a factory problem. They are a specification translation problem. The buyer specifies cover thickness to DIN 22102 or AS 1332. The Chinese factory works to GB/T 9770. The standards measure cover thickness differently, and without a clear bridging note in the drawing, the factory defaults to what it knows.

Three recurring failure points

1. Carry-side vs return-side ratio

The buyer specifies a carry/return ratio that the factory interprets as a single-side average. The buyer ends up with a belt that looks correct on the datasheet and fails in the first six months under load. The fix is to specify both values explicitly on the drawing, not as a ratio.

2. Skive allowance at splices

Some specifications include a manufacturing tolerance for skiving at splices. Factories working to GB/T treat this differently to ISO 22721. If nobody flags it during drawing review, the factory builds to its own tolerance.

3. Cover grade designation gaps

Cover grades like N, M, SHR in DIN do not have direct equivalents in GB/T. The factory picks the closest local compound. That is not a substitution — it is a gap in the handoff. The mechanical properties may be close, but for high-temperature, oil-resistant, or fire-resistant duties (common in mining), close is not equivalent.

What we do

Before any rubber goods order goes to a Chinese manufacturer, our technical team translates the specification requirements into the local standard, documents every discrepancy, gets client sign-off, and embeds the bridging notes directly in the factory drawings.

If you are sourcing conveyor belting from China and want to see what a proper spec translation review looks like, we are happy to walk through one.

Contact: sales@meritustech.com · +86 134 8206 1802 · www.meritustech.com