S235JR steel (1.0038): properties, composition, equivalents
S235JR (1.0038) is the EN 10025-2 structural steel with 235 MPa minimum yield, 360–510 MPa tensile and 27 J impact at +20 °C. Composition, equivalents, old names.
What is S235JR?
S235JR is the entry grade of EN 10025-2, the European standard for hot-rolled non-alloy structural steels. The designation encodes everything a buyer needs: S = structural, 235 = minimum yield strength in MPa for thicknesses up to 16 mm, J = 27 J Charpy energy, R = tested at room temperature (+20 °C). Its Werkstoff number is 1.0038.
It is a low-carbon (≤ 0.17 %) steel supplied as-rolled (+AR) or normalized/normalizing-rolled (+N). Because the carbon equivalent is capped at 0.35 %, it welds without preheat in all common thicknesses, which is why S235JR is the default material for secondary steelwork, general fabrication, light frames and any part where stiffness rather than strength governs the design.
S235JR replaced DIN St37-2 and BS 4360 40B in 1994; the old names survive on legacy drawings, so this page lists them alongside the ASTM, JIS, GB and GOST cross-references.
S235JR chemical composition
| Element | Mass % | Note |
|---|---|---|
| C | ≤ 0.17 | ≤ 40 mm nominal thickness; 0.20 % above 40 mm (product analysis +0.03) |
| Mn | ≤ 1.4 | |
| P | ≤ 0.035 | |
| S | ≤ 0.035 | |
| N | ≤ 0.012 | may be exceeded if Al ≥ 0.020 % or other N-binding elements are present |
| Cu | ≤ 0.55 |
Ladle analysis per EN 10025-2:2019 Table 2. Si is not limited for S235JR; CEV maximum 0.35 % up to 30 mm, 0.38 % up to 150 mm.
S235JR mechanical properties
| Thickness / condition | Yield strength ReH / Rp0.2 MPa (ksi) | Tensile strength Rm MPa (ksi) | Elongation A % | Hardness |
|---|---|---|---|---|
| ≤ 16 mm | 235 (34.1) | 360–510 (52.2–74.0) | 26 | ≈ 100–140 HB (typical) |
| > 16 ≤ 40 mm | 225 (32.6) | 360–510 (52.2–74.0) | 26 | — |
| > 40 ≤ 63 mm | 215 (31.2) | 360–510 (52.2–74.0) | 25 | — |
| > 63 ≤ 80 mm | 215 (31.2) | 360–510 (52.2–74.0) | 24 | — |
| > 80 ≤ 100 mm | 215 (31.2) | 360–510 (52.2–74.0) | 24 | — |
| > 100 ≤ 150 mm | 195 (28.3) | 350–500 (50.8–72.5) | 22 | — |
| > 150 ≤ 200 mm | 185 (26.8) | 340–490 (49.3–71.1) | 21 | — |
Rm range applies to 3–100 mm; elongation for L0 = 5.65√S0, longitudinal; transverse values are 2 points lower for flat products. Hardness is not specified by the standard — the HB figure is typical for as-rolled material.
Impact toughness
S235JR requires a minimum Charpy V-notch energy of 27 J at 20 °C (longitudinal, ≥ 10 mm thick). The 'JR' suffix means J = 27 J and R = room temperature (+20 °C). S235J0 is tested at 0 °C and S235J2 at −20 °C.
S235JR equivalent grades
| Grade | System | Match | Why / differences |
|---|---|---|---|
| St37-2 | DIN (superseded German) | Identical | Direct successor (1.0038). S235JR guarantees 27 J at +20 °C which St37-2 did not; ordering S235JR always satisfies an St37-2 requirement. |
| S235JRH | EN (European) | Identical | Same steel as flat/long product to EN 10025-2; the H suffix only marks the hollow-section delivery standard. |
| A36 | ASTM / ASME | Near | A36 yield 250 MPa (36 ksi) and Rm 400–550 MPa are slightly higher; no impact requirement. Widely accepted as the US counterpart. |
| A283 Gr. C | ASTM / ASME | Near | Yield 205 MPa, Rm 380–515 MPa; plate only, no Charpy requirement. |
| S235J0 | EN (European) | Near | Same chemistry limits with P/S 0.030 %; impact 27 J at 0 °C instead of +20 °C. |
| S195T | EN (European) | Near | The strip from which most S195T tube is actually made; S235JR coil certified to EN 10255 requirements. |
| Q235B | GB/T (China) | Near | GB/T 700 Q235B: yield 235 MPa, Rm 370–500 MPa, 27 J at +20 °C — the closest Chinese match; C max 0.20 %. |
| St3sp | GOST (Russia/CIS) | Near | GOST 380 St3sp (killed): yield 245 MPa ≤ 20 mm, Rm 370–480 MPa; impact tested at +20 °C. |
| IS 2062 E250 BR | IS (India) | Near | Yield 250 MPa, Rm 410 MPa min; BR = impact tested at room temperature. |
| SS400 | JIS (Japan) | Near | JIS G3101 SS400: yield 245 MPa (≤16 mm), Rm 400–510 MPa; no chemistry limits beyond P and S, no impact test. |
| S275JR | EN (European) | Functional | Next strength class (275 MPa); substitutes upward for strength but is not identical. |
| C15 | EN (European) | Functional | Structural steel of similar carbon; not a case-hardening quality (no hardenability or cleanliness control). |
| DC01 | EN (European) | Functional | Hot-rolled structural steel of similar chemistry; not a cold-rolled forming grade and not interchangeable in surface or gauge. |
| DD11 | EN (European) | Functional | Structural steel of similar chemistry with guaranteed 235 MPa yield and impact; DD11 has no minimum yield guarantee for structural design. |
| S250GD | EN (European) | Functional | Uncoated hot-rolled structural steel of similar strength for members that will be post-galvanized. |
Identical = same composition and mechanical limits within rounding. Near = one limit differs (e.g. carbon max or impact temperature). Functional = interchangeable for most uses after an engineering check. Full cross-reference for S235JR →
Old and superseded designations
| Old name | Standard | Note |
|---|---|---|
| St37-2 | DIN 17100 (withdrawn 1994) | Most common legacy name; still on many drawings and in Turkish, Polish and Middle-East specifications. |
| Fe360B | EN 10025:1990 / UNI 7070 | Renamed S235JR in EN 10025:1993. |
| 40A / 40B | BS 4360 (withdrawn 1994) | 40B is the closer match (impact at +20 °C). |
| E24-2 | NF A 35-501 (withdrawn) | French designation. |
| S235JRG2 | EN 10025:1993 | Fully killed variant; merged into S235JR (1.0038) in EN 10025-2:2004. |
Product forms and tolerance standards
Product forms: hot-rolled plate and wide flat, hot-rolled coil and sheet, sections (IPE, HEA/HEB, UPN, angles), merchant bar and flat bar, welded hollow sections (as S235JRH, EN 10219).
Dimensional tolerances: plate: EN 10029; hot-rolled coil/sheet: EN 10051; sections: EN 10034 (I/H), EN 10279 (channels), EN 10056-2 (angles); flat bar: EN 10058.
Key property values
S235JR yield strength
The minimum yield strength (ReH) of S235JR is 235 MPa (34.1 ksi) for thicknesses up to 16 mm, dropping stepwise to 215 MPa at 40–100 mm and 185 MPa at 150–200 mm. Design codes (EN 1993-1-1) use fy = 235 MPa for t ≤ 40 mm and 215 MPa for 40–80 mm.
S235JR tensile strength
Tensile strength (Rm) is 360–510 MPa (52–74 ksi) for 3–100 mm. Mill certificates for coil typically show 400–440 MPa.
S235JR hardness
EN 10025-2 does not specify hardness. As-rolled S235JR measures roughly 100–140 HB (≈ 110–150 HV), which is why it is easily drilled, sheared and punched.
Density, modulus and thermal properties
Density 7.85 g/cm³, Young's modulus 210 GPa, shear modulus 81 GPa, Poisson's ratio 0.30, coefficient of thermal expansion 12 × 10⁻⁶/K (20–100 °C), thermal conductivity ≈ 50 W/m·K. These are the EN 1993-1-1 design values common to all structural carbon steels.
Carbon equivalent (CEV)
Maximum CEV is 0.35 % for t ≤ 30 mm, 0.35 % for 30–40 mm, 0.38 % for 40–150 mm and 0.40 % for 150–250 mm (EN 10025-2 Table 4).
Weldability
S235JR is fully weldable by all arc processes (MMA, MAG, SAW, TIG) without preheat up to about 40 mm thickness thanks to its low CEV (≤ 0.35 %). Use E42 / G42 class consumables (EN ISO 2560 / 14341). For thick sections or high restraint, follow EN 1011-2 for preheat and interpass control; hydrogen-controlled electrodes are recommended above 25 mm.
Machining, forming and heat treatment
Machinability is good in the as-rolled condition (index ≈ 70 % relative to 1212 free-cutting steel). Cold forming: minimum inside bend radius per EN 10025-2 Table 7 is 1.0 t for t ≤ 2.5 mm up to 2.0 t for 8–16 mm (transverse); most mills achieve 1 t on coil. Hot forming 900–1100 °C. Normalizing 890–930 °C is possible but rarely needed. S235JR is not intended for hardening; case-hardening is not applicable because of the low carbon content.
Typical applications
- General steel construction: purlins, bracing, secondary beams, platforms and stairs
- Welded frames, machine bases and guards
- Storage racks and shelving profiles
- Hollow sections for fences, handrails and light structures (as S235JRH)
- Base plates, cleats and gusset plates
- Pre-painted and hot-dip galvanized steelwork (good galvanizing response when Si is controlled)
S235JR compared with related grades
Frequently asked questions
What does S235JR mean?
S = structural steel, 235 = minimum yield strength in MPa (up to 16 mm), J = 27 J Charpy impact energy, R = tested at room temperature (+20 °C). The full designation may carry a delivery condition, e.g. S235JR+AR (as rolled) or S235JR+N (normalized).
What is the ASTM equivalent of S235JR?
ASTM A36 is the usual substitute: 250 MPa yield and 400–550 MPa tensile, slightly stronger and without a Charpy requirement. For plate, A283 Grade C is also used. Neither is identical, so the match is graded 'near'.
Is S235JR the same as St37?
Practically yes. St37-2 (DIN 17100) was replaced by S235JR in 1994. St37-2 had no guaranteed impact value while S235JR guarantees 27 J at +20 °C, so S235JR always satisfies an St37-2 requirement, but not strictly the other way round.
Can S235JR be hardened?
No. With ≤ 0.17 % carbon it does not respond to quench hardening and it is not a case-hardening grade. Choose C45 or 42CrMo4 for hardened parts.
What is the difference between S235JR and S235J2?
Same strength; the impact test temperature differs: +20 °C for JR, 0 °C for J0, −20 °C for J2. S235J2 also has lower P and S limits (0.025 %) and is always fully killed.
Related grades
Verified against EN 10025-2:2019; EN 10025-2:2019 Tables 2, 4, 7 and 8; EN 1993-1-1:2005 Table 3.1. Last checked: September 2026.