Steel S355J2W +M
Heat-treated state
EN 1.8965 · also Corten B
+M = thermomechanically controlled processed
Pick when the lowest carbon equivalent and best weldability/toughness are needed in thinner weathering plate and coil; do not hot-form above ~580 °C.
Values for the +M condition
Other S355J2W tempers and conditions
S355J2W is listed in 3 conditions; see the grade overview at S355J2W.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Normalized | Choose for heavier plate and for the most uniform, finest grain with best low-temperature toughness and flame-cutting behaviour. | 375 | 510 | 26 | 155 HB | — |
+ARDefault Hot rolled | Standard stocked condition for weathering plate, sections and coil up to moderate thickness; cheapest and most available. | 380 | 520 | 24 | 160 HB | — |
+MThis page Thermomechanically controlled processed | Pick when the lowest carbon equivalent and best weldability/toughness are needed in thinner weathering plate and coil; do not hot-form above ~580 °C. | 400 | 520 | 25 | 165 HB | 8 % IACS |
What is S355J2W +M?
S355J2W +M is S355J2W heat treated to +M — pick when the lowest carbon equivalent and best weldability/toughness are needed in thinner weathering plate and coil; do not hot-form above ~580 °C. S355J2W +M has a yield strength of 400 MPa (58 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 60% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi). S355J2W +M has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). +AR is the default condition FabDigit quotes; +M is available on request or by drawing note.
Advantages
- Good corrosion resistance — 30/100, better than 95% of steel grades
- Tough — resists crack growth — 140 MPa·√m (127.4 ksi·√in), better than 94% of steel grades
- Forms and bends easily — 76/100, better than 91% of steel grades
- Readily welded — 86/100, better than 85% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
S355J2W +M properties
Typical room-temperature values for S355J2W +M; 22 are specific to this condition. Other listed values are S355J2W reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
S355J2W +M has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
S355J2W +M has a yield strength of 400 MPa (58 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 60% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
S355J2W +M is rated for continuous service to 350°C (662 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
S355J2W +M conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), better than 95% of steel grades.
Sustainability4
Producing a kilogram of S355J2W +M takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability8
S355J2W +M's machinability is fair (52/100, better than 52% of steel grades); weldability excellent (86/100); formability very good (76/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S355J2W +M
Is S355J2W easy to machine?
Machines like a 355 MPa HSLA plate (~55–60 % of AISI 1212) — rigid setups, sharp carbide, moderate speeds; slightly gummy chips from the Cu/Cr content.
Can S355J2W be welded?
Readily welded by SMAW/GMAW/SAW with weathering-matched consumables (e.g. E8018-W2, ER80S-G, Ni-Cu wires); CEV ≈ 0.45–0.52 so preheat 50–150 °C for thick or restrained joints and control hydrogen.
Can S355J2W be formed, bent or molded?
Cold bends to about 2t inner radius transverse (3t longitudinal) in ≤16 mm plate; hot forming 900–1050 °C should be followed by normalizing, and +M material must not be heated above ~580 °C.
What surface finishes work on S355J2W?
Normally left bare to develop the patina (shot-blast mill scale off first and design for free drainage/run-off control); can also be painted after blasting or metallised where chlorides are present.
S355J2W chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CEN 10025-5 ladle analysis | ≤ 0.16 | 0.12 |
| Si | ≤ 0.5 | 0.35 |
| Mn | 0.5 – 1.5 | 1.1 |
| PS355J2WP variant has 0.06–0.15 P | ≤ 0.03 | 0.02 |
| S≤0.025 for J2 quality in many mill practices | ≤ 0.03 | 0.01 |
| Crpatina former | 0.4 – 0.8 | 0.6 |
| Cuprimary weathering element | 0.25 – 0.55 | 0.35 |
| Ni | ≤ 0.65 | 0.2 |
| Mooptional | ≤ 0.3 | — |
| Zroptional | ≤ 0.15 | — |
| Nhigher if N-binding elements present | ≤ 0.01 | 0.01 |
| Nb+V+Timicro-alloy additions, total, mill option | ≤ 0.22 | 0.05 |
| Fe | balance | — |
S355J2W +M — frequently asked
What is S355J2W +M used for?
S355J2W +M is typically used for bridges, towers and outdoor architectural steelwork. In short: paint-free weathering plate; corten B equivalent; J2 toughness outdoors.
What is the yield strength of S355J2W +M?
S355J2W +M has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is S355J2W +M easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines like a 355 MPa HSLA plate (~55–60 % of AISI 1212) — rigid setups, sharp carbide, moderate speeds; slightly gummy chips from the Cu/Cr content.
Can S355J2W +M be welded?
Yes — weldability is rated excellent (86/100). Readily welded by SMAW/GMAW/SAW with weathering-matched consumables (e.g. E8018-W2, ER80S-G, Ni-Cu wires); CEV ≈ 0.45–0.52 so preheat 50–150 °C for thick or restrained joints and control hydrogen.
What surface finishes work on S355J2W +M?
Normally left bare to develop the patina (shot-blast mill scale off first and design for free drainage/run-off control); can also be painted after blasting or metallised where chlorides are present.
Can S355J2W +M be formed, bent or molded?
Cold bends to about 2t inner radius transverse (3t longitudinal) in ≤16 mm plate; hot forming 900–1050 °C should be followed by normalizing, and +M material must not be heated above ~580 °C.
What is the maximum service temperature of S355J2W +M?
S355J2W +M is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10025-5: Hot rolled products of structural steels — Technical delivery conditions for structural steels with improved atmospheric corrosion resistance — CEN (2019)
- ASTM A588/A588M — High-Strength Low-Alloy Structural Steel with Atmospheric Corrosion Resistance — ASTM International (2019)
- GB/T 4171 (Q355NH / Q355GNH) — SAC (2008)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (weathering steels) — ASM International (2005)
- EN 1993-1-1 Eurocode 3 — Design of steel structures (physical constants) — CEN (2005)
- Weathering steel plate datasheets (COR-TEN A/B type products) — SSAB / ArcelorMittal / Baosteel (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.