What Does CNAS Accreditation Mean on a Chinese Test Report?

Which part of the report does the CNAS mark cover?

The CNAS mark covers only the test items that fall inside the laboratory's scope of accreditation. Everything else printed on the same page sits outside that scope, and the report is required to say so.

CNAS accredits a laboratory for defined test items and the method standards it uses. The item list is the boundary. Composition, hardness, case depth, tensile properties, diameter, roundness, straightness, length and surface roughness are typical examples, and each one has to appear in the laboratory's scope before the mark can be attached to it.

Under CNAS-R01:2023, a report bearing the CNAS mark that includes non-accredited items must clearly identify them as outside the scope of accreditation, and opinions and interpretations outside the scope must also be marked. A mixed report is therefore normal and not a defect. A row or a footnote marked as not accredited is not an error; it is an item the laboratory has not been assessed for.

Read the report with that boundary in mind. Ask which items are accredited, ask for the accreditation number, and check that the items you actually care about are the accredited ones. If your acceptance decision hangs on a single property, such as case depth on an induction-hardened shaft, confirm that this property appears inside the scope rather than assuming the mark covers the whole page.

What does a CNAS report on submitted samples prove?

A submitted-sample report proves the tested items of the tested sample. It does not prove the lot, and it does not prove later deliveries.

Under Article 11 of the Measures for the Supervision and Administration of Inspection and Testing Institutions, when an institution tests samples submitted by a client, the report is responsible for the conformity of the tested items of those samples, while the client is responsible for the representativeness and authenticity of the samples. A report on submitted samples therefore states results only for those samples and the listed items; it says nothing about untested items and does not automatically represent the whole lot or later deliveries.

That division of responsibility is the part overseas buyers most often miss. If a supplier sends three bars to a laboratory, the report describes three bars. Whether those three bars represent the 500 bars on the order is a sampling question, and under the rule above it sits with whoever submitted the samples.

So decide early who takes the sample and how it is linked to the goods. If the report has to support an incoming inspection decision, have the sample identified by heat number or bar number, and keep the retained sample until the delivery arrives and has been checked.

How do I verify a CNAS report from a Chinese laboratory?

Verify the laboratory and the item list, not the logo. The report should carry the laboratory's accreditation number and a reference you can check with the laboratory itself.

Steps that work in practice:

1. Match the report reference and date to the document you were given, and keep the original file rather than a photograph of it.
2. Take the accreditation number from the report and confirm it with the issuing laboratory. CNAS numbers use the form CNAS L followed by digits.
3. Ask the laboratory to confirm that each test item on the report is inside its accredited scope, and to point out any item that is not.
4. Check the sample description against what you ordered: grade, condition, surface, diameter, and the product name used on the drawing.
5. Check whether the report states that the samples were submitted by the client, because that determines what the results can be used for.
6. Where the report carries a QR code or a laboratory contact block, use it to reach the laboratory directly rather than through the supplier.

Anything you cannot confirm with the laboratory — an item that does not appear in its scope, or a report reference the laboratory does not recognize — should be treated as unverified until it is resolved. A clear scan and a matching reference number are usually enough; a laboratory will confirm or deny its own report.

Does a CNAS mark mean the bars themselves are certified?

No. The accreditation mark belongs to the laboratory and to the tested items, not to the product.

CNAS accreditation is granted to a laboratory for defined tests. It is not a product certification scheme, and it is not a statement that a production system has been certified. The accreditation mark must not be used on samples or products in a way that implies product certification, and it does not travel with the bars.

For a buyer, that has a practical consequence. A report with a CNAS mark answers one question: did the tested item on the tested sample meet the requirement quoted on the report, as measured by a laboratory assessed for that item? It does not answer whether the rest of the order is the same, whether the process is under control, or whether the material suits your application.

Use the report as one input. Dimensional and surface checks on receipt, the mill certificate supplied with the order, and the acceptance values on your own drawing remain the working controls on the goods. The report supports those controls; it does not replace them.

What does a CNAS report look like for chrome-plated and ground bar stock?

For bar stock the common items are chemical composition, hardness, tensile properties, case depth, diameter, roundness, straightness, length and surface roughness — and on a real report, not all of them carry the same marks.

Yixin Precision Machinery (Changzhou) publishes lab test reports for sample bars tested in July 2026 by Jiangsu Yinshi, which holds CMA and CNAS accreditation, and by TPM, which holds CNAS accreditation. One case-depth report carries no CMA or CNAS mark, so that result carries no statement of accreditation — which is exactly the distinction this article explains. Each published report has a QR code for verification with the laboratory.

These published reports are one-off third-party checks on sample bars, not routine per-order testing. Where an order needs third-party inspection, it is arranged on request.

What to put in your RFQ

• The product name and condition exactly as they appear in the catalogue, for example 45 Steel Q&T Ground Round Bar or 40Cr Q&T Chrome-Plated Bar.
• The grade and standard: Grade 45 to GB/T 699-2015, or 40Cr or 42CrMo to GB/T 3077-2015.
• The test items you want reported, with acceptance values: composition, hardness, case depth, tensile properties, diameter, roundness, straightness, length or surface roughness.
• Whether the report must come from a laboratory with CNAS accreditation for those specific items, and whether any item outside that scope must be identified as such on the report.
• How the sample will be taken and identified — bar number, heat number, or the lot the sample is meant to represent.
• Whether per-order third-party inspection should be arranged on request, and which items it should cover.
• Diameter, tolerance, length and quantity, so that the report can be matched against the goods on arrival.

Summary

A CNAS mark on a Chinese test report is a statement about a laboratory and a defined list of test items. It tells you the laboratory has been accredited for those items. It tells you nothing about items the report does not list. On submitted samples, the result belongs to the sample tested, and responsibility for whether that sample represents the lot sits with the client. For chrome-plated and ground bar stock, the report is one input alongside your drawing requirements, dimensional and surface checks, and the mill certificate. Read the scope, verify the number with the laboratory, and state your test items in the enquiry.

References

• CNAS-R01:2023 — rules on use of the CNAS accreditation mark: a report bearing the CNAS mark that includes non-accredited items must clearly identify them as outside the scope of accreditation, and opinions and interpretations outside the scope must also be marked.
• Measures for the Supervision and Administration of Inspection and Testing Institutions, Article 11 — responsibility for submitted samples: the institution is responsible for the conformity of the tested items of the samples, the client for the representativeness and authenticity of the samples.
• GB/T 699-2015 — standard cited in the catalogue for Grade 45 bar stock.
• GB/T 3077-2015 — standard cited in the catalogue for 40Cr and 42CrMo bar stock.