A36 vs S235JR: differences explained
A36 vs S235JR: US and EU mild structural steels — yield 250 vs 235 MPa, tensile 400–550 vs 360–510 MPa, Charpy none vs 27 J at +20 °C, carbon ≤ 0.25–0.29 vs 0.17 %. Substitution rules in both directions and the S275 option.
Overview
A36 and S235JR are the everyday structural steels of the two largest engineering traditions, and projects that cross the Atlantic — or use American drawings with European supply — need to know exactly how they differ. A36 is slightly stronger (250 vs 235 MPa yield, 400–550 vs 360–510 MPa tensile) but has no impact requirement and a looser chemistry (carbon up to 0.25–0.29 %); S235JR guarantees 27 J at +20 °C, caps carbon at 0.17 % and CEV at 0.35 %, which makes it marginally more weldable and tougher.
The practical consequences: S235JR can replace A36 only if the designer accepts a 6 % lower yield (or the design was not strength-critical); A36 can replace S235JR only where no Charpy value is required. Where an exact-or-better European substitute is wanted, S275JR (275 MPa) is the safe choice. The table lays out every number.
A36 vs S235JR side by side
| Property | A36 | S235JR |
|---|---|---|
| Standard | ASTM A36/A36M-19 | EN 10025-2:2019 |
| Number | UNS K02600 | 1.0038 |
| Product forms | plate, shapes (W/S/C/L), bar | plate, coil, sections, bar, hollow (S235JRH) |
| Min. yield | 250 MPa (36 ksi) ≤ 200 mm; 220 MPa above | 235 MPa ≤ 16 mm; 225 to 40; 215 to 100 mm |
| Tensile | 400–550 MPa (58–80 ksi) | 360–510 MPa (52–74 ksi) |
| Elongation | ≥ 20 % (200 mm) / 23 % (50 mm) | ≥ 26 % (L0 = 5.65√S0, ≤ 40 mm) |
| Impact toughness | not required (S5 optional) | 27 J at +20 °C (J0: 0 °C, J2: −20 °C) |
| Carbon max | 0.25 % (plate ≤ 40 mm) to 0.29 % | 0.17 % (≤ 40 mm) / 0.20 % |
| Mn | 0.80–1.20 % (plate > 20 mm) | ≤ 1.40 % |
| P / S max | 0.030 / 0.030 % | 0.035 / 0.035 % |
| Carbon equivalent | not limited (typ. 0.30–0.40) | ≤ 0.35 % (≤ 30 mm) |
| Deoxidation / grain size | not specified (semi-killed allowed) | FN (killed optional), fine grain optional |
| Typical hardness | 119–159 HB | 100–140 HB |
| Design value | Fy = 36 ksi (AISC) | fy = 235 MPa (EN 1993-1-1) |
| Yield ratio (typical) | ≈ 0.65–0.75 | ≈ 0.60–0.70 |
| Weldability | excellent; AWS D1.1 preheat by thickness | excellent; no preheat to ~40 mm |
| Old / related names | A7 (predecessor), A709-36, SA-36 | St37-2, Fe360B, 40B, S235JRG2 |
| Nearest exact-or-better EU substitute | — | S275JR (275 MPa) |
| Nearest exact-or-better US substitute | A572 Gr. 42 / A36 for S235 | — |
Which should you choose?
Replacing A36 with a European grade: use S275JR to be at or above A36 on every strength value; use S235JR only if the design allows 235 MPa (many do, since A36 is often used where deflection governs) and note that you gain a Charpy guarantee.
Replacing S235JR with a US grade: A36 covers the strength with margin. If the European drawing calls S235J0/J2 or specifies impact values, order A36 with supplementary S5 (Charpy at the required temperature) or use A709 Grade 36.
Welding across the pair is unproblematic — both use E70XX / E42 class consumables — but on thick A36 (> 40 mm, C up to 0.29 %) apply AWS D1.1 preheat; S235JR rarely needs it.
- US/Canadian projects designed to AISC or AASHTO
- Plate and shapes where 250 MPa is used in the calculation
- Bar and plate for general fabrication in North America
- When European drawings call S235 and no impact value is specified
- EU/UK/Middle East projects designed to EN 1993
- Members requiring a Charpy guarantee (+20 °C, or J0/J2 for colder)
- Cold-formed and galvanized light steelwork (lower carbon)
- When US drawings call A36 for non-strength-critical members (else S275JR)
Frequently asked questions
Is A36 equivalent to S235JR?
They are near equivalents, not identical. A36 has 250 MPa yield and 400–550 MPa tensile with no impact requirement; S235JR has 235 MPa yield, 360–510 MPa tensile and a guaranteed 27 J at +20 °C. S235JR is graded 'near' to A36; S275JR is the European grade that meets or exceeds A36 in strength.
Can S235JR replace A36?
Only where the design does not need the full 250 MPa (about 6 % less yield), or after a check. For a like-for-like or better substitute, use S275JR (275 MPa yield, 410–560 MPa tensile).
Can A36 replace S235JR?
Yes for strength. If the European specification requires impact toughness (S235JR's 27 J at +20 °C, or J0/J2), order A36 with supplementary requirement S5 for Charpy testing.
Which is more weldable, A36 or S235JR?
S235JR marginally: carbon ≤ 0.17 % and CEV ≤ 0.35 % versus A36's carbon up to 0.25–0.29 % with no CEV limit. Both are prequalified for standard procedures; thick A36 needs AWS D1.1 preheat above 19 mm.
What is A36 in DIN and JIS?
DIN St37-2 (now S235JR) and JIS SS400 (245 MPa yield) are the usual cross-references; GB Q235B and GOST St3sp likewise. None is identical.
Is S235J2 the same as A36?
No — S235J2 has the same strength as S235JR but is impact tested at −20 °C and is fully killed with lower P/S. A36 has no Charpy requirement, so it is 'near' at best; use A36 + S5 or A709 Grade 36 with zone requirements.
Related comparisons
Verified against ASTM A36/A36M-19; EN 10025-2:2019. Last checked: September 2026.