What is GB/T 17421?
GB/T stands for "Guobiao/Tuijian" (State Standard / Recommended). GB/T 17421 is the direct Chinese adoption of the ISO 230 series.
In practice, these standards are often mapped together by part number, but you should always verify the revision year and clause references used in your contract.
Key Equivalencies
| Chinese Standard | ISO Equivalent | Subject |
|---|---|---|
| GB/T 17421.1 | ISO 230-1 | Geometric Accuracy |
| GB/T 17421.2 | ISO 230-2 | Positioning Accuracy |
| GB/T 17421.3 | ISO 230-3 | Thermal Effects |
Common Pitfalls for Importers
While the standard itself is solid, the application of the standard can vary in lower-tier factories.
1. Methodology Drift
Acceptance reports can look similar while using different internal test scripts. If the same metric name is produced by different procedures, results are not directly comparable.
Tip: Always request underlying measurement records, not only summary PDFs.
2. Thermal Conditions
Environmental conditions can materially influence measured results. Make sure ambient condition, warm-up, and stabilization details are documented in the report set.
Why This Matters
Understanding GB/T 17421 gives you leverage. If a manufacturer makes an accuracy claim, ask for the exact clause, test procedure, and uncertainty statement behind that number.
Related Calculators
These calculators help turn standards and acceptance data into machine-selection, maintenance, and investment decisions.
Compare machine-fit assumptions after you review the builder’s GB/T 17421 or ISO 230 evidence.
Model accuracy-related service exposure, inspection intervals, and downtime budgeting around acceptance risk.
Bring standards-driven risk, service cost, and resale assumptions into the lifecycle decision.