Comparison
4340 vs 34CrNiMo6
AISI/SAE 4340 and 34CrNiMo6 / 1.6582 are closely related Ni-Cr-Mo quenched and tempered steels and are often cross-referenced in drawings and purchasing. They are not automatically identical. Chemistry, mechanical properties, condition and certificate must be checked. At European mills, 34CrNiMo6 and 1.6582 are what the 3.1 certificate typically carries.
The designations
The drawing may say 4340, 34CrNiMo6 or 1.6582. The USA and much of Asian purchasing use 4340. Danish and European mills write 34CrNiMo6 and 1.6582. Also closely related are 4337, EN24 / 817M40 and SS 2541 – still not an automatic swap.
- 34CrNiMo6 – EN 10083-3, the name Danish drawings most often use
- 1.6582 – W.Nr. on the certificate
- AISI/SAE 4340 – closely related American designation
When 4340 / 34CrNiMo6 is not enough
For very large cross-sections or tightened core requirements, the usual step is to 30CrNiMo8 (1.6580). That is a different W.Nr. – not another spelling of 4340.
What to write on the enquiry
Write 4340, 34CrNiMo6 or 1.6582 together with the standard and condition the drawing requires (+QT, hardness, Ø and length). We supply the EN material the mill can certify, and we tell you if the American specification requires something we cannot carry.
Frequently asked questions
- Is 4340 the same as 34CrNiMo6?
- No, not automatically. AISI 4340 is a closely related American designation that is often cross-referenced to 34CrNiMo6 / 1.6582. Requirements for chemistry, properties, condition and certificate must be checked before substitution.
- What does the 3.1 certificate say?
- The name and W.Nr. the mill has issued – typically 34CrNiMo6 and 1.6582. 4340 may appear as a cross-reference. We do not invent a 4340 certificate if the heat is certified as 34CrNiMo6.
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Send your enquiry
State grade, dimensions and quantity — or attach a drawing. We reply with a quote.