Enter a designation from a drawing, enquiry or certificate — e.g. S355J2+N, 42CrMo4+QT, X5CrNi18-10 or the steel number 1.4301. The decoder breaks the name down into its parts, explains each one and shows comparable grades in other standards.
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Enter a steel designation or choose a grade from the list.
Breakdown of the designation
This steel in other standards
| EN | DIN (former) | PN (former, Poland) | ASTM / AISI / SAE | JIS | BS (former) |
|---|
These are approximate equivalents, not one-to-one substitutes — the standards differ in composition and requirements. PN are former Polish standards. A dash (—) means we found no confirmation in a manufacturer’s data sheet or a table of the standard, so we give no value.
More: Steel designations: S355J2+N, C45, 42CrMo4
Link to this result — to paste into an e-mail or enquiry:
How the decoder works and what it does not do
- The decoder reads the name according to the rules of EN 10027-1 (steel names) and explains the structure of the number according to EN 10027-2 (steel numbers). The same letter can mean different things depending on its position — L at the start means steel for line pipe, in the impact symbol 60 J, and at the end, as in S355NL, low temperature. The decoder takes this into account.
- Element contents are nominal — they follow from the naming rule (e.g. Cr × 4), not from a heat analysis. The actual composition ranges are given in the product standard.
- The decoder has a catalogue of grades from product standards (EN 10025, EN 10210, EN 10219, EN 10149, EN 10028, EN 10083, EN 10084, EN 10087, EN 10088, ISO 4957). A grade from the catalogue gets a green frame with the standard, the steel number and the delivery conditions provided for by the standard. A grade outside the catalogue does not appear in the standards we know — the breakdown then follows the naming rules only, and the decoder suggests the closest existing grades.
- We give the steel number and equivalents in other systems (DIN, PN, ASTM/AISI/SAE, JIS, BS) only where they appear in a manufacturer’s data sheet, in a table of the standard or in two independent distributor tables. No confirmation = a dash, we do not guess.
- A part that cannot be read according to the standard is shown as not recognized. A symbol with two possible meanings is marked uncertain, with both meanings.
- Former and foreign names (e.g. St52-3, St3S, Ck45, stal 45, AISI 304, 316L, SAE 4140, SUS304) are recognized: the decoder gives the approximate EN equivalent — all of them where there are several — and breaks the EN grade down. These are not one-to-one substitutes.
- Groups of the standard rarely encountered in machining (flat products for cold forming such as DC01, tinmill products, electrical steel, rails, prestressing steel) are not broken down in detail.
Have a drawing of your part? Send it for a quotation. Email the drawing to biuro@hardpower.pl or describe the part in the contact form — we will reply and ask for the drawing. HARDPOWER is a CNC machining company in Szczecin, Poland, certified to ISO 9001:2015 (PRS certificate no. NC-3170).
Equivalents of common steel grades
The grades we see most often on drawings for machining: steel number, product standard and equivalents in former DIN standards, former Polish PN standards and the AISI/SAE system. Click a name to see the full breakdown.
| EN grade | Number | Product standard | What the name means | DIN (former) | PN (former, Poland) | ASTM / AISI / SAE |
|---|---|---|---|---|---|---|
| S235JR | 1.0038 | EN 10025-2 | Structural steel with a minimum yield strength of 235 MPa, with an impact energy of at least 27 J at +20 °C. | St 37-2 RSt 37-2 | St3S | — |
| S355J2 | 1.0577 | EN 10025-2 | Structural steel with a minimum yield strength of 355 MPa, with an impact energy of at least 27 J at −20 °C. | St 52-3 St 52-3 N | 18G2A — comparable to S355; sources do not assign it to a single variant | — |
| S355NL | 1.0546 | EN 10025-3 | Structural steel with a minimum yield strength of 355 MPa, fine-grain, normalized or normalized rolled, for low temperatures. | TStE 355 EStE 355 | 18G2A — comparable to S355; sources do not assign it to a single variant | — |
| C45 | 1.0503 | EN 10083-2 | Non-alloy steel (Mn below 1%) with approx. 0.45% carbon. | C45 | 45 | 1045 |
| 42CrMo4 | 1.7225 | EN 10083-3 | Steel designated by chemical composition: approx. 0.42% C, approx. 1% Cr, with an addition of Mo (content not given in the name). | 42CrMo4 | 40HM | 4140 4140H |
| 16MnCr5 | 1.7131 | EN 10084 | Steel designated by chemical composition: approx. 0.16% C, approx. 1.25% Mn, with an addition of Cr (content not given in the name). | 16MnCr5 | 16HG | 5115 |
| 100Cr6 | 1.3505 | EN ISO 683-17 | Steel designated by chemical composition: approx. 1% C, approx. 1.5% Cr. | — | ŁH15 | 52100 |
| X5CrNi18-10 | 1.4301 | EN 10088-2/-3 | High-alloy steel: approx. 0.05% C, approx. 18% Cr, approx. 10% Ni. | — | 0H18N9 | 304 S30400 |
| X2CrNiMo17-12-2 | 1.4404 | EN 10088-2/-3 | High-alloy steel: approx. 0.02% C, approx. 17% Cr, approx. 12% Ni, approx. 2% Mo. | X2CrNiMo17-13-2 | 00H17N14M2 | 316L S31603 |
| X153CrMoV12 | 1.2379 | EN ISO 4957 | High-alloy steel: approx. 1.53% C, approx. 12% Cr, with an addition of Mo, V (content not given in the name). | X155CrVMo12-1 | NC11LV | D2 T30402 |
The equivalents are approximate, not one-to-one substitutes. A dash (—) means we found no confirmation in a manufacturer’s data sheet or a table of the standard.
How a steel name is built
- By application and properties: a letter indicating the application and a number, e.g. S355J2+N. S stands for structural steel, 355 is the minimum yield strength in MPa (for the smallest thickness range), J2 means at least 27 J impact energy at −20 °C, and +N the normalized delivery condition.
- By chemical composition, e.g. C45 (non-alloy steel, approx. 0.45% carbon), 42CrMo4 (approx. 0.42% C, approx. 1% Cr (the figure 4 divided by the factor 4) and an addition of Mo) and X5CrNi18-10 (high-alloy steel: approx. 0.05% C, 18% Cr, 10% Ni).
- Steel number 1.XXXX to EN 10027-2, e.g. 1.0577 for S355J2. The number does not include the delivery condition, so S355J2 and S355J2+N have the same number.
Full explanation with examples: Steel designations: S355J2+N, C45, 42CrMo4. What we make from steel: CNC steel machining. Other tools: ISO 286 fits calculator, ISO 2768 general tolerances, all online workshop tools.
Have a drawing of your part? Send it for a quotation. Email the drawing to biuro@hardpower.pl or describe the part in the contact form — we will reply and ask for the drawing. HARDPOWER is a CNC machining company in Szczecin, Poland, certified to ISO 9001:2015 (PRS certificate no. NC-3170).
Prepared by: HARDPOWER, Szczecin, Poland — CNC machining. Technical questions: biuro@hardpower.pl, +48 91 817 28 77.
Rules to EN 10027-1:2016 and EN 10027-2. This decoder is a workshop aid. The text of EN 10027-1 and of the relevant product standard is binding.
