Steel S355JR-SR (Stress relieved)
Heat-treated state
EN S355JR · JIS SM490A · GB Q355B
Use for welded fabrications and heavily machined frames where residual stress and distortion must be controlled.
Values for the SR condition
Other S355JR tempers and conditions
S355JR is listed in 6 conditions; see the grade overview at S355JR.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
as-rolled, t = 40–80 mm | Thick as-rolled plate; use when heavy sections are needed, noting the standard's reduced minimum yield. | 350 | 520 | 24 | 155 HB | 9 % IACS |
SRThis page Stress relieved | Use for welded fabrications and heavily machined frames where residual stress and distortion must be controlled. | 380 | 530 | 26 | 152 HB | 9 % IACS |
Normalized | Choose for fine, uniform grain, better through-thickness toughness and post-forming property recovery on heavy plate. | 395 | 540 | 27 | 155 HB | — |
ARDefault as-rolled (hot rolled), t ≤ 16 mm | Standard stocked hot-rolled plate, section and coil; cheapest route for general structures. | 400 | 550 | 25 | 160 HB | — |
Thermomechanically controlled processed | Pick for lower carbon equivalent, best weldability with minimal preheat and good low-temperature toughness in plate. | 425 | 520 | 28 | 165 HB | 9 % IACS |
Cold drawn | Cold-drawn bright bar for shafts and machined parts needing tight tolerance, better finish and higher strength. | 520 | 620 | 12 | 200 HB | 9 % IACS |
What is S355JR-SR?
S355JR-SR is S355JR heat treated to SR — use for welded fabrications and heavily machined frames where residual stress and distortion must be controlled. S355JR-SR has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 68% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi). S355JR-SR 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; SR is available on request or by drawing note.
Advantages
- Easy to machine — 62/100, better than 89% of steel grades
- Readily welded — 88/100, better than 87% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
S355JR-SR properties
Typical room-temperature values for S355JR-SR; 22 are specific to this condition. Other listed values are S355JR reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
S355JR-SR 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
S355JR-SR has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 68% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
S355JR-SR 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
S355JR-SR conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of S355JR-SR takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
S355JR-SR's machinability is good (62/100, better than 89% of steel grades); weldability excellent (88/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S355JR-SR
Is S355JR easy to machine?
Machines like a medium-carbon steel — moderate tool wear, gummy chips in the as-rolled condition; use coated carbide, positive rake and generous coolant.
Can S355JR be welded?
Excellent weldability by all arc processes with CEV ≤ 0.45; preheat 100–150 °C only for thick sections or restraint, and use low-hydrogen consumables (E7018 / ER70S-6).
Can S355JR be formed, bent or molded?
Cold bends readily at 2–3 t inner radius across the rolling direction; hot forming 900–1050 °C followed by normalizing restores toughness.
What surface finishes work on S355JR?
No natural corrosion protection — shot-blast to Sa 2.5 then zinc-rich primer, epoxy paint, or hot-dip galvanize per EN ISO 1461.
S355JR 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 0.24 % for t ≤ 16 mm (EN 10025-2) | ≤ 0.24 | 0.18 |
| Si | ≤ 0.55 | 0.25 |
| Mn | ≤ 1.6 | 1.35 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Nnot applicable if sufficient N-binding elements present | ≤ 0.01 | 0.01 |
| Cu | ≤ 0.55 | 0.2 |
| CEVcarbon equivalent (IIW), t ≤ 30 mm | ≤ 0.45 | 0.42 |
| Fe | balance | — |
S355JR-SR — frequently asked
What is S355JR-SR used for?
S355JR-SR is typically used for heavy structural steelwork, cranes, bridges, mobile equipment chassis and load-bearing frames. In short: weldable 355 MPa structural steel; stronger than S235/S275; widely stocked plate and section.
What is the yield strength of S355JR-SR?
S355JR-SR has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 68% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is S355JR-SR easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines like a medium-carbon steel — moderate tool wear, gummy chips in the as-rolled condition; use coated carbide, positive rake and generous coolant.
Can S355JR-SR be welded?
Yes — weldability is rated excellent (88/100). Excellent weldability by all arc processes with CEV ≤ 0.45; preheat 100–150 °C only for thick sections or restraint, and use low-hydrogen consumables (E7018 / ER70S-6).
What surface finishes work on S355JR-SR?
No natural corrosion protection — shot-blast to Sa 2.5 then zinc-rich primer, epoxy paint, or hot-dip galvanize per EN ISO 1461.
Can S355JR-SR be formed, bent or molded?
Cold bends readily at 2–3 t inner radius across the rolling direction; hot forming 900–1050 °C followed by normalizing restores toughness.
What is the maximum service temperature of S355JR-SR?
S355JR-SR 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.
What is the difference between S355JR-AR and S355JR-CD?
AR is the default condition — standard stocked hot-rolled plate, section and coil; cheapest route for general structures. CD: cold-drawn bright bar for shafts and machined parts needing tight tolerance, better finish and higher strength. Yield strength is 400 MPa in AR versus 520 MPa in CD.
Sources
- EN 10025-2 Hot rolled products of structural steels — Non-alloy structural steels — CEN (2019)
- ASTM A572/A572M Grade 50 — ASTM International (2021)
- EN 1993-1-1 / EN 1993-1-2 Eurocode 3 design of steel structures — CEN (2005)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Structural steel S355 plate data sheets — SSAB / Dillinger / thyssenkrupp (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.