Views: 0 Author: Site Editor Publish Time: 2026-10-23 Origin: Site
When purchasing martensitic stainless steel grades such as 420J1, 420J2 or 4Cr13, suppliers typically provide a Mill Test Certificate (MTC). The grade, chemical composition and test results on the certificate should match both the purchase requirements and the material delivered. For blades, cutting tools and wear-resistant components with specified hardness requirements, buyers also need to check which material condition the test results represent.
Start with the material labels. Compare the heat number, coil number or product identification number against the MTC and packing list. The heat number identifies the melting batch, while coil numbers and other identifiers help distinguish individual products. When purchasing slit martensitic stainless steel strip, the original mill certificate may show the width of the parent coil. Processing records should link the finished strips to that parent coil. A sample MTC supplied during quotation is for reference only; the shipment should be accompanied by documentation covering the actual material delivered.
Check the applicable standard alongside the grade designation. The grade, standard edition and product form agreed in the purchase order should be clearly identified in the supply documents. For example, if the order specifies 420J2 but the certificate only states “420,” ask the supplier to clarify rather than assuming they are identical. When comparing Chinese, Japanese, European or Russian grades, review the specific technical requirements instead of relying solely on a grade equivalence chart.
The chemical composition section should contain actual results for the material supplied. Carbon and chromium are key elements to check when purchasing martensitic stainless steel, but all other specified elements must also be reviewed. Compare each result with the limits in the agreed standard, taking account of the requirements applicable to heat analysis and product analysis. Typical compositions in product literature and standard specification ranges do not replace actual batch test results.
Read the mechanical properties together with the delivery condition. The same martensitic stainless steel grade can have significantly different properties in the annealed and quenched-and-tempered conditions. If the material is supplied after heat treatment, the original certificate for annealed material alone does not demonstrate compliance with the final hardness requirement. Test results corresponding to the relevant heat-treatment batch are also needed.
For hardness results, check whether the scale is HRC, HV or HBW; the numbers cannot be compared directly across different scales. Where the order specifies tensile strength, yield strength or elongation, review the results, units and test conditions. For stainless steel plate and precision strip, nominal thickness and width on the certificate do not replace dimensional tolerance inspection. Flatness, edge camber, burr height and surface roughness may also require separate inspection records.
Some customers require metallographic examination, salt spray testing or other additional tests. Whether these tests are required, which methods apply and what constitutes an acceptable result should be agreed before ordering. If a result is absent from the MTC, ask whether a separate report is available or whether additional testing is needed. Do not assume the material has passed an unreported test.
If the order requires EN 10204 Type 3.1, check the document type and its validation details. Type 3.1 defines an inspection document category; it does not replace the applicable material specification. The certificate is validated by an inspection representative authorized by the manufacturer and independent of the production department. It is not, by itself, a third-party inspection report. The certificate number, issuer, date and validation details should be clear and verifiable.
When requesting a quotation from DSM for martensitic stainless steel plate, coils or precision strip, please include the grade, dimensions, delivery condition, applicable standards and testing requirements. For orders involving slitting, cutting to length or heat treatment, confirm in advance which original mill certificates, processing records and finished-material inspection reports will be provided. This gives your receiving team a clear basis for checking the material against the agreed requirements.
