Steel S355J0 +AR (Hot rolled)
Heat-treated state · default condition
EN S355J0 · GB Q355C
Standard mill delivery condition for plate, section and bar up to 16 mm — cheapest and most widely stocked.
Values for the +AR condition
Other S355J0 tempers and conditions
S355J0 is listed in 6 conditions; see the grade overview at S355J0.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed / soft annealed | Used before heavy cold forming or deep machining; lowest strength and hardness, best ductility. | 330 | 490 | 30 | 140 HB | 8.7 % IACS |
+AR | Heavy plate; reduced minimum yield (335 MPa at 40–63 mm, 325 MPa at 63–80 mm, 315 MPa at 80–100 mm) and lower UTS band. | 350 | 500 | 23 | 152 HB | 8.6 % IACS |
+AR | Medium plate and heavy section; yield minimum drops to 345 MPa per EN 10025-2 thickness table. | 370 | 530 | 24 | 158 HB | 8.6 % IACS |
+ARDefaultThis page Hot rolled | Standard mill delivery condition for plate, section and bar up to 16 mm — cheapest and most widely stocked. | 380 | 540 | 25 | 160 HB | 8.6 % IACS |
Normalized | Choose for heavy sections, hot-formed parts or when uniform fine-grain toughness through thickness is required. | 385 | 530 | 27 | 155 HB | 8.6 % IACS |
Cold drawn | Pick for close-tolerance shafting and machined parts; higher strength and better surface, but residual stresses and lower ductility. | 500 | 620 | 14 | 190 HB | 8.6 % IACS |
What is S355J0 +AR?
S355J0 +AR is S355J0 heat treated to +AR — standard mill delivery condition for plate, section and bar up to 16 mm — cheapest and most widely stocked. S355J0 +AR has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 68% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi). S355J0 +AR 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).
Advantages
- Readily welded — 88/100, better than 87% of steel grades
- Tough — resists crack growth — 120 MPa·√m (109.2 ksi·√in), better than 81% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
S355J0 +AR properties
Typical room-temperature values for S355J0 +AR; 22 are specific to this condition. Other listed values are S355J0 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
S355J0 +AR 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
S355J0 +AR has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 68% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
S355J0 +AR is rated for continuous service to 400°C (752 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), better than 75% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
S355J0 +AR conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of S355J0 +AR takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
S355J0 +AR's machinability is good (60/100, better than 83% of steel grades); weldability excellent (88/100); formability good (65/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S355J0 +AR
Is S355J0 easy to machine?
Machines like ordinary C-Mn steel at ~58 % of AISI 1212; use coated carbide, moderate speeds, and expect stringy chips in the as-rolled condition.
Can S355J0 be welded?
Excellent weldability by SMAW/GMAW/SAW with matching low-hydrogen consumables; CEV ≤ 0.47 means preheat is usually only needed above ~30–40 mm or in restrained joints.
Can S355J0 be formed, bent or molded?
Good cold bending (minimum bend radius ≈ 1.5–2.5 t depending on thickness and direction); hot forming 900–1050 °C followed by normalizing restores toughness.
What surface finishes work on S355J0?
No anodizing; protect by shot blasting plus zinc-rich primer/paint system, hot-dip galvanizing or metallizing — bare steel rusts quickly outdoors.
S355J0 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 |
|---|---|---|
| Cmax 0.22 for flat products t > 40 mm | ≤ 0.2 | 0.17 |
| Si | ≤ 0.55 | 0.25 |
| Mn | ≤ 1.6 | 1.4 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Nlimit waived if sufficient N-binding elements present | ≤ 0.01 | 0.01 |
| Cu | ≤ 0.55 | 0.15 |
| Fe | balance | — |
S355J0 +AR — frequently asked
What is S355J0 +AR used for?
S355J0 +AR is typically used for structural beams, welded frames, bridges, cranes and machine bases. In short: standard 355 MPa structural steel; highly weldable, CEV ≤ 0.47; 0 °C impact toughness.
What is the yield strength of S355J0 +AR?
S355J0 +AR has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 68% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is S355J0 +AR easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machines like ordinary C-Mn steel at ~58 % of AISI 1212; use coated carbide, moderate speeds, and expect stringy chips in the as-rolled condition.
Can S355J0 +AR be welded?
Yes — weldability is rated excellent (88/100). Excellent weldability by SMAW/GMAW/SAW with matching low-hydrogen consumables; CEV ≤ 0.47 means preheat is usually only needed above ~30–40 mm or in restrained joints.
What surface finishes work on S355J0 +AR?
No anodizing; protect by shot blasting plus zinc-rich primer/paint system, hot-dip galvanizing or metallizing — bare steel rusts quickly outdoors.
Can S355J0 +AR be formed, bent or molded?
Good cold bending (minimum bend radius ≈ 1.5–2.5 t depending on thickness and direction); hot forming 900–1050 °C followed by normalizing restores toughness.
What is the maximum service temperature of S355J0 +AR?
S355J0 +AR 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.
What is the difference between S355J0 +AR and S355J0-CD?
+AR is the default condition — standard mill delivery condition for plate, section and bar up to 16 mm — cheapest and most widely stocked. CD: pick for close-tolerance shafting and machined parts; higher strength and better surface, but residual stresses and lower ductility. Yield strength is 380 MPa in +AR versus 500 MPa in CD.
Sources
- EN 10025-2 Hot rolled products of structural steels — Non-alloy structural steels — CEN (2019)
- GB/T 1591 High strength low alloy structural steels (Q355C) — SAC (2018)
- ASTM A572/A572M Grade 50 — ASTM International (2021)
- EN 1993-1-1 Eurocode 3: Design of steel structures — CEN (2005)
- ASM Handbook Vol.1 Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Structural steel plate S355 delivery conditions — SSAB / Dillinger (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.