S355J2 Pipes and Tubes
S355J2 is the structural steel grade that engineers reach for when a hollow section must deliver both high strength and guaranteed toughness in cold or dynamically loaded conditions. Produced to EN 10025-2, the J2 sub-grade designation confirms Charpy V-notch impact testing at −20 °C — the property that separates it from standard S355JR hollow sections on demanding project specifications.
In pipe and tube form, S355J2 combines the load-bearing efficiency of 355 MPa minimum yield strength with the geometric advantages of hollow sections — high section modulus relative to weight, closed profiles that resist torsion, and clean aesthetics for exposed structural applications. These characteristics make S355J2 pipes and tubes the default specification for offshore structural tubulars, heavy crane columns, pile casings, and structural hollow sections in cold-climate construction where both strength and toughness must be certified.
Mechanical Properties
| Property | Value | Unit |
|---|---|---|
| Tensile Strength | 470 – 630 | MPa |
| Yield Strength (min., t ≤ 16 mm) | 355 | MPa |
| Yield Strength (min., 16–40 mm) | 345 | MPa |
| Yield Strength (min., 40–63 mm) | 335 | MPa |
| Elongation (min.) | 22 | % |
| Charpy Impact at −20 °C (min.) | 27 | J |
| Brinell Hardness | 152 – 187 | HB |
| Density | 7.85 | g/cm³ |
| Modulus of Elasticity | 210 | GPa |
Chemical Composition
| Element | Max. Content (%) |
|---|---|
| Carbon (C) | 0.22 |
| Silicon (Si) | 0.55 |
| Manganese (Mn) | 1.60 |
| Phosphorus (P) | 0.030 |
| Sulfur (S) | 0.030 |
| Nitrogen (N) | 0.012 |
| Carbon Equivalent (CE) | 0.43 max |
Tighter P and S limits in S355J2 compared to S355JR contribute directly to the improved low-temperature toughness that defines the sub-grade.
Product Types & Manufacturing Routes
- Seamless Pipes & Tubes (EN 10210-1): Produced by hot piercing and rolling without a longitudinal weld seam. Seamless S355J2 pipe offers uniform wall thickness, higher pressure ratings, and superior fatigue performance. Specified for structural columns, hydraulic cylinders, piling, and pressure-bearing tubular applications.
- Welded Structural Hollow Sections — SHS / RHS / CHS (EN 10219-1): Cold-formed welded hollow sections produced from S355J2 coil. Square (SHS), rectangular (RHS), and circular (CHS) hollow sections are the standard form for structural columns, beams, trusses, and portal frames. Cold-formed sections carry the EN 10219-1 designation; hot-finished sections carry EN 10210-1.
- Hot-Finished Hollow Sections (EN 10210-1): Produced by hot forming of welded tube, removing residual stresses from the cold-forming process. Hot-finished sections have more consistent mechanical properties through the wall thickness and are preferred for primary structural applications and offshore use.
- ERW Pipes (EN 10217-1): Electric resistance welded pipes produced from S355J2 strip for structural and fluid-conveying applications where seamless is not required.
Hot-Finished vs Cold-Formed S355J2 Hollow Sections
| Property | Hot-Finished (EN 10210) | Cold-Formed (EN 10219) |
|---|---|---|
| Residual Stress | Low | Higher (from cold forming) |
| Corner Radius | Larger | Tighter |
| Wall Thickness Tolerance | Tighter | Standard |
| Mechanical Uniformity | Better | Good |
| Cost | Higher | Lower |
| Preferred Use | Primary structure, offshore | Secondary structure, general fab. |
Applications
- Offshore Jacket & Topside Structures: Tubular chord and brace members in offshore jacket legs, topside support structures, and subsea pile sleeves where S355J2 impact certification is the minimum structural requirement.
- Structural Columns & Trusses: SHS and RHS hollow sections for columns, rafters, and truss chords in industrial buildings, sports halls, and long-span roofs where hollow section efficiency reduces steel tonnage.
- Crane Columns & Boom Structures: Seamless and hot-finished S355J2 tubes for crane mast sections, jib tubes, and lattice boom chords where dynamic loading and cold-climate service require impact-tested material.
- Piling & Foundation Tubulars: Large-diameter S355J2 seamless and welded pipe sections used as steel piles, casing pipes, and cofferdam elements in foundation engineering.
- Bridges & Infrastructure: Circular hollow sections (CHS) for arch ribs, hangers, bracing members, and pedestrian bridge structures where aesthetics, torsional efficiency, and EN 1993 compliance are all required.
- Hydraulic & Mechanical Cylinders: Cold-drawn seamless S355J2 tube for hydraulic cylinder barrels and mechanical tube applications requiring consistent bore, wall, and material properties.
- Energy Sector Structures: Wind turbine tower transition pieces, support structures for solar tracking systems, and structural frames in power generation facilities requiring high-strength tubular material.
Weldability & Processing
S355J2 pipe and tube welds well using SMAW, GMAW, FCAW, SAW, and GTAW processes. CE of up to 0.43 permits welding without preheat for wall thicknesses below 25 mm at ambient temperatures above 5 °C. For wall thicknesses above 25 mm or in cold ambient conditions, a preheat of 75–150 °C is recommended.
For impact-critical applications — offshore, crane, bridge — welding consumables must be selected to provide a minimum 27 J at −20 °C at the weld deposit, consistent with the base material impact requirement. Using consumables without a specified impact classification undermines the toughness assurance the J2 sub-grade provides.
Post-weld heat treatment is not required for standard structural applications but may be specified for high-restraint joints, fatigue-critical connections, or where project specifications mandate stress relief.
Dimensional Range
| Product Form | OD / Size Range | Wall Thickness |
|---|---|---|
| Seamless Pipe (EN 10210-1) | 21.3 mm – 610 mm OD | 3.2 mm – 100 mm |
| CHS Hot-Finished (EN 10210-1) | 26.9 mm – 508 mm OD | 3.2 mm – 40 mm |
| SHS Hot-Finished (EN 10210-1) | 40 × 40 mm – 400 × 400 mm | 3.0 mm – 40 mm |
| RHS Hot-Finished (EN 10210-1) | 50 × 30 mm – 500 × 300 mm | 3.0 mm – 40 mm |
| CHS Cold-Formed (EN 10219-1) | 21.3 mm – 406.4 mm OD | 2.0 mm – 20 mm |
| SHS / RHS Cold-Formed (EN 10219-1) | 20 × 20 mm – 400 × 200 mm | 2.0 mm – 16 mm |
Manufacturing Standards & Equivalents
- EN 10025-2: Chemical and mechanical requirements for S355J2 material
- EN 10210-1: Hot-finished structural hollow sections of non-alloy and fine grain steels
- EN 10219-1: Cold-formed welded structural hollow sections of non-alloy and fine grain steels
- EN 10216-1: Seamless steel tubes for pressure purposes
- EN 10217-1: Welded steel tubes for pressure purposes
Quality Assurance
- Mechanical Testing: Mechanical Testing — Tensile, yield, and elongation testing is performed per EN ISO 6892-1 for every heat. Charpy V-notch impact testing at −20 °C (min. 27 J) is mandatory for all S355J2 material and is conducted per EN ISO 148-1. For seamless pipe and hot-finished hollow sections, hardness testing across the pipe wall confirms uniform heat treatment.
- Dimensional Accuracy: Dimensional Accuracy — Outer diameter, wall thickness, length, straightness, and squareness of ends are verified against EN 10210 or EN 10219 tolerances as applicable. For seamless pipe, eccentricity (wall thickness variation) is additionally measured to confirm uniform wall geometry critical for pressure and fatigue applications.
- Weldability Tests: Weldability Tests — Weld procedure qualifications are conducted per EN ISO 15614-1. For offshore and crane applications, heat-affected zone Charpy impact testing at −20 °C is performed alongside weld tensile and guided bend tests to confirm full joint toughness compliance.
FAQs
Products
Industry We Serve
- Oil & Gas industries
- Chemical process industries
- Pump and valve in high pressure component
- Food industries
- Pulp and paper industry
- Aerospace industry
- Power plant
- Mechanical component
- Sugar industry
- Cement industry