Steel S355K2W +AR-THICK (+AR)
Finish state
EN 1.8967 · also Corten B
Same steel supplied as heavy plate; specify when the design must use the reduced thickness-dependent yield values of EN 10025-5.
Values for the +AR-THICK condition
Other S355K2W tempers and conditions
S355K2W is listed in 3 conditions; see the grade overview at S355K2W.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+AR-THICKThis page +AR | Same steel supplied as heavy plate; specify when the design must use the reduced thickness-dependent yield values of EN 10025-5. | 355 | 510 | 25 | 150 HB | 8.5 % IACS |
Normalized | Choose for thick plate or where a fine, uniform grain and the most reliable -20 °C toughness are required (bridges, heavy welded structures). | 385 | 520 | 28 | 150 HB | — |
+ARDefault Hot rolled | Standard mill delivery condition for plate, coil and sections; use unless a normalized structure is specified. | 390 | 530 | 26 | 155 HB | — |
What is S355K2W +AR-THICK?
S355K2W +AR-THICK is S355K2W supplied in the +AR-THICK condition — same steel supplied as heavy plate; specify when the design must use the reduced thickness-dependent yield values of EN 10025-5. S355K2W +AR-THICK has a yield strength of 355 MPa (51.5 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 73% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi). S355K2W +AR-THICK has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F). +AR is the default condition FabDigit quotes; +AR-THICK is available on request or by drawing note.
Advantages
- Good corrosion resistance — 32/100, better than 96% of steel grades
- Forms and bends easily — 66/100, better than 83% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
- Readily welded — 76/100, better than 77% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
S355K2W +AR-THICK properties
Typical room-temperature values for S355K2W +AR-THICK; 22 are specific to this condition. Other listed values are S355K2W reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
S355K2W +AR-THICK has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F).
Mechanical16
S355K2W +AR-THICK has a yield strength of 355 MPa (51.5 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 73% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
S355K2W +AR-THICK is rated for continuous service to 400°C (752 °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
S355K2W +AR-THICK conducts electricity at 8.5 % IACS, better than 63% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), better than 96% of steel grades.
Sustainability4
Producing a kilogram of S355K2W +AR-THICK takes about 26 MJ of energy and emits 2.2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
S355K2W +AR-THICK's machinability is good (57/100, better than 71% of steel grades); weldability very good (76/100); formability good (66/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S355K2W +AR-THICK
Is S355K2W easy to machine?
Machines like a 355 MPa C-Mn steel but slightly gummier from Cu/Ni — use positive-rake carbide, moderate speed and generous feed to break chips.
Can S355K2W be welded?
Readily welded by SMAW/GMAW/SAW with weathering-grade consumables (e.g. Cu-Ni-Cr filler) so the weld patinas with the base metal; preheat 50–100 °C for thick or restrained joints and control hydrogen.
Can S355K2W be formed, bent or molded?
Good cold bending; use a bend radius of about 2t for t ≤ 16 mm across the grain, or hot form at 900–1050 °C followed by normalizing when toughness is critical.
What surface finishes work on S355K2W?
Normally left bare so the protective patina forms (allow 1–3 years, provide drainage and avoid pockets that stay wet); if paint is required, blast to Sa 2½ and prime — no anodizing possible.
S355K2W 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 |
|---|---|---|
| C | ≤ 0.16 | 0.12 |
| Si | ≤ 0.5 | 0.35 |
| Mn | 0.5 – 1.5 | 1 |
| P0.035 max for long products | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.02 |
| Crpatina former | 0.4 – 0.8 | 0.6 |
| Cupatina former | 0.25 – 0.55 | 0.35 |
| Ni | ≤ 0.65 | 0.3 |
| Nbmicro-alloying, sum Nb+Ti+V limited | ≤ 0.06 | — |
| V | ≤ 0.12 | — |
| Ti | ≤ 0.05 | — |
| Zroptional | ≤ 0.15 | — |
| Fe | balance | — |
S355K2W +AR-THICK — frequently asked
What is S355K2W +AR-THICK used for?
S355K2W +AR-THICK is typically used for heavy exposed structural members, bridges in demanding climates and critical outdoor infrastructure. In short: toughest S355 weathering class; paint-free exposed structures; guaranteed -20 °C impact energy.
What is the yield strength of S355K2W +AR-THICK?
S355K2W +AR-THICK has a typical yield strength of 355 MPa (51.5 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 73% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is S355K2W +AR-THICK easy to machine?
Reasonably — machinability is rated good (57/100, better than 71% of steel grades). Machines like a 355 MPa C-Mn steel but slightly gummier from Cu/Ni — use positive-rake carbide, moderate speed and generous feed to break chips.
Can S355K2W +AR-THICK be welded?
Yes — weldability is rated very good (76/100). Readily welded by SMAW/GMAW/SAW with weathering-grade consumables (e.g. Cu-Ni-Cr filler) so the weld patinas with the base metal; preheat 50–100 °C for thick or restrained joints and control hydrogen.
What surface finishes work on S355K2W +AR-THICK?
Normally left bare so the protective patina forms (allow 1–3 years, provide drainage and avoid pockets that stay wet); if paint is required, blast to Sa 2½ and prime — no anodizing possible.
Can S355K2W +AR-THICK be formed, bent or molded?
Good cold bending; use a bend radius of about 2t for t ≤ 16 mm across the grain, or hot form at 900–1050 °C followed by normalizing when toughness is critical.
What is the maximum service temperature of S355K2W +AR-THICK?
S355K2W +AR-THICK is rated for continuous use to about 400°C (752 °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)
- EN 10027-2 / material number 1.8967 — CEN (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASTM A588/A588M (comparable weathering steel) — ASTM (2019)
- Weathering steel plate datasheets (Corten B / S355J2W-K2W) — European plate mills (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.