St 37-2 vs S235JR: differences explained
St 37-2 and S235JR are the same steel under two names: DIN 17100 was withdrawn in 1994 and EN 10025-2 replaced it. The differences are in the paperwork, not the metal.
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Overview
This is not really a comparison, it is a translation. St 37-2 was withdrawn when DIN 17100 was replaced by EN 10025 in 1994, and its successor is S235JR, material number 1.0038. A mill today cannot supply St 37-2 against a valid standard; what it supplies is S235JR with the old name written on the order for the customer's comfort.
The name survives because a generation of drawings, price lists and workshop habits use it — in Türkiye, Germany, Austria and across the Balkans, "St 37" is still what people say when they mean ordinary structural steel. The question worth answering is therefore not which is better, but what changes when the drawing says one and the certificate says the other.
St 37-2 vs S235JR side by side
| Property | St 37-2 | S235JR |
|---|---|---|
| Standard | DIN 17100 (withdrawn 1994) | EN 10025-2:2019 |
| Material number | 1.0037 (St 37-2) | 1.0038 (S235JR) |
| Status today | Not a current standard — cannot be certified against | Current, CE-markable under EN 1090 |
| Min. yield ReH, ≤ 16 mm | 235 MPa | 235 MPa |
| Tensile Rm | 340–470 MPa (DIN value) | 360–510 MPa |
| Elongation | 25–26 % | 26 % |
| Impact test | Not required for St 37-2 | 27 J at +20 °C |
| Max C, ≤ 16 mm | 0.17 % | 0.17 % |
| Max P / S | 0.045 / 0.045 % | 0.035 / 0.035 % |
| Deoxidation | Rimming permitted in the -2 class | Rimming not permitted (FN) |
| Sub-grades | St 37-2, USt 37-2, RSt 37-2, St 37-3 | S235JR, S235J0, S235J2 |
| Closest one-to-one | RSt 37-2 → S235JR | S235JR → RSt 37-2 |
| CE marking | Not possible | Yes, with a DoP |
| Typical use today | Old drawings, workshop language, repairs | Everything current |
| ASTM parallel | A283 Gr C / A36 with caveats | A283 Gr C / A36 with caveats |
| JIS parallel | SS400 | SS400 |
| GB parallel | Q235B | Q235B |
| Certificate you will receive | EN 10204 3.1 stating S235JR | EN 10204 3.1 stating S235JR |
| Price difference | None — it is the same material | None |
| Where the old name still appears | Türkiye, Germany, Austria, Balkans | — |
Which should you choose?
Order S235JR. If the drawing says St 37-2, write "S235JR (ex St 37-2, 1.0037)" on the purchase order and the certificate will match the drawing without anyone having to interpret it later. The two real differences worth knowing: the old -2 class allowed rimming steel and looser phosphorus and sulphur, and St 37-2 carried no impact requirement, so if the application is cold or welded and thick, the modern grade to ask for is S235J0 or S235J2 rather than a plain JR.
- Only as a reference: when reading a drawing, a stock list or a machine manual older than the mid-1990s
- When matching an existing structure and the designer wants the old designation recorded
- In workshop conversation, where "St 37" remains the common name for ordinary mild steel
- Every current order — it is the grade a mill can certify and a fabricator can CE mark
- Any structure under EN 1090, where the declaration of performance needs an EN grade
- When an impact value has to appear on the certificate (JR at +20 °C, J0 at 0 °C, J2 at −20 °C)
- Export work, where the old DIN name causes customs and inspection questions
Frequently asked questions
Is St 37 the same as S235JR?
In practice yes. St 37-2 from the withdrawn DIN 17100 was replaced by S235JR in EN 10025-2; the yield strength is identical at 235 MPa. EN 10025-2 tightens phosphorus and sulphur, forbids rimming steel and adds an impact test.
Can I still buy St 37?
You can order it by that name and you will receive S235JR. No mill can issue a certificate against a withdrawn standard.
What is St 37 in ASTM?
The closest common grades are A283 Grade C and A36, but neither is identical: A36 has a higher tensile range and different chemistry limits. Treat it as functional equivalence, not a substitution.
What was RSt 37-2?
The killed-steel version of St 37-2 — R for beruhigt, meaning deoxidised. It is the sub-grade that maps most cleanly onto S235JR, because modern EN steel is never rimming.
Is St 37 the same as St 37-2?
St 37 is the family; the suffix is the quality class. St 37-2 is the basic class, St 37-3 added impact testing and corresponds roughly to S235J0 or S235J2.
What about St 52?
St 52-3 is the higher-strength member of the same withdrawn family and corresponds to S355JR or S355J2 depending on the impact class.
Related comparisons
Verified against EN 10025-2:2019 · DIN 17100 (withdrawn). Last checked: October 2026.