Comparison
4140 vs 42CrMo4
AISI/SAE 4140 and 42CrMo4 / 1.7225 are closely related steel grades and are often cross-referenced, but they are not automatically identical specifications. Always check the specific standard, delivery condition and material certificate. 4140 is the American designation, 42CrMo4 the European one to EN 10083-3, and 1.7225 is the W.Nr.
The designations and what they cover
The drawing may say 4140, 42CrMo4 or 1.7225. Purchasers in the USA and Asia often use 4140. Danish and European mills write 42CrMo4 and 1.7225 on the 3.1 certificate. We supply the EN material the mill can certify. If the drawing requires the American specification, it must be on the enquiry – a cross-reference is not in itself an approved substitution.
- 42CrMo4 – EN 10083-3, the name Danish drawings most often use
- 1.7225 – W.Nr., what the mill and the certificate use
- AISI/SAE 4140 – closely related American grade, often cross-referenced
What can differ
Chemical composition, mechanical properties, heat treatment and delivery condition must be checked against the specific specification before 4140 and 42CrMo4 are substituted for each other. 42CrMoS4 (1.7227) is the sister grade with raised sulphur for machining; the certificate says 1.7227, not 1.7225. 4140H is an American hardenability guarantee – it is not a third W.Nr. but a requirement that has to be specified. Condition (+QT, rolled) and diameter govern the part more than the name does.
What to write on the enquiry
Write 4140, 42CrMo4 or 1.7225 together with the standard the drawing requires. Add +QT or the specified hardness, plus Ø and length. On the quotation and certificate we state the name and W.Nr. the mill issues, and we tell you if the drawing's specification cannot be met by the material we can source.
Frequently asked questions
- Is 4140 the same as 42CrMo4?
- AISI/SAE 4140 is a closely related American steel grade that is often cross-referenced to 42CrMo4 / 1.7225. They should not, however, automatically be regarded as identical. Requirements for chemical composition, mechanical properties, heat treatment and delivery condition must be checked against the specific specification and the material certificate before substitution.
- Can I order 4140 and receive 42CrMo4?
- Often yes, but it is a substitution that must be agreed. We lock in 42CrMo4 / 1.7225 at the mill when the PO says 4140, provided the requirements for chemistry, properties and condition have been checked. If you need the American standard text documented, it must be on the order.
- What does the 3.1 certificate say?
- The name and W.Nr. the mill has issued – typically 42CrMo4 and 1.7225. AISI 4140 may appear as a cross-reference. We do not invent a 4140 certificate if the heat is certified as 42CrMo4.
- Is 42CrMoS4 also 4140?
- Same chromium-molybdenum family, raised sulphur for machining. The W.Nr. is 1.7227, not 1.7225. The drawing may cross-reference both to 4140, but they are not the same specification. We supply the variant the certificate can carry.
- What about 4140H?
- 4140H is AISI with a hardenability guarantee. If it has to be covered, it is a requirement for condition, cross-section and documentation that must be specified – not something 42CrMo4 automatically fulfils. We do not promise an H certificate the mill has not issued.
- When is 4140 / 42CrMo4 not enough?
- When diameter and core requirements mean that 1.7225 loses the core. Then it is 34CrNiMo6 (1.6582) – not another 4140 designation.
Read more
Send your enquiry
State grade, dimensions and quantity — or attach a drawing. We reply with a quote.