S355J2

1.0577

Hot-rolled non-alloy structural steel with specified impact toughness · EN 10025-2:2019 · EN 10025-1:2004 · EN 10027-1 · EN 10027-2

S355J2 is the fully killed J2 toughness quality of the EN 10025-2 S355 non-alloy structural-steel family. It combines a minimum yield strength of 355 MPa at thicknesses up to 16 mm with a specified longitudinal Charpy V-notch energy of 27 J at −20 °C. Strength decreases with product thickness, and the grade designation alone does not define the product form, dimensional standard, delivery condition, through-thickness properties, cold-forming suitability or inspection document.

Structural steel; 355 MPa minimum yield at t ≤ 16 mm; J2 impact qualityDesignation meaning · The 355 MPa value does not apply at every thickness.
27 J minimum Charpy V-notch energy at −20 °CSpecified toughness · Longitudinal test pieces; applicability and specimen-size rules depend on product dimensions.
FF — fully killedDeoxidation · Nitrogen-binding elements must be present in sufficient quantity.
0.45% to 0.49%, depending on thicknessMaximum heat-analysis CEV · A special 0.54% limit applies to long products over 150 mm through 250 mm.
Up to 400 mm for J2 qualityFlat-product thickness range · Requirements above 250 mm apply to flat products; long-product coverage generally ends at 250 mm for S355J2.
Must be identified on the inspection documentDelivery condition · Unless explicitly ordered, the permitted condition may be selected by the manufacturer within the product-form rules.

Overview

Designation system: EN 10027-1 steel name and EN 10027-2 steel number
Product forms: Hot-rolled plate and sheet, Hot-rolled strip and products cut from strip, Wide flats, Hot-rolled sections, Hot-rolled bars and other long products, Semi-finished products for subsequent rolling, subject to order agreement
Condition: +AR — as rolled, +N — normalized or normalized rolled, +M — thermomechanically rolled; permitted for long products and hot-rolled strip, not quarto plate
Density: 7850 kg/m³ (Nominal volumetric mass used by EN 10025-2 for calculating mass from nominal dimensions; not a heat-specific measured property.)

What the designation defines—and what it does not

The name is property-based. “S” identifies structural steel, “355” is the minimum specified upper yield strength ReH in MPa for the smallest standard thickness range, and “J2” identifies the impact-quality requirement. Under EN 10025-2, S355J2 is steel number 1.0577.

EN 10025-2 governs hot-rolled flat and long products. It does not govern finished structural hollow sections or tubes; designations such as S355J2H belong to separate hollow-section standards. S355J2 also does not by itself specify improved through-thickness ductility, guaranteed cold-forming performance, weather resistance, pressure-equipment suitability, ultrasonic quality, dimensional tolerances or a particular delivery condition.

A Charpy test temperature is not automatically a permissible minimum service temperature. Structural toughness selection also depends on thickness, stress level, detail category, loading rate, fabrication, consequence of failure and the applicable design code.

Chemical composition and weldability controls

Maximum heat-analysis composition under EN 10025-2:2019

Element or requirement	Limit, mass %	Qualification
C	0.20 max.	Nominal thickness ≤ 30 mm
C	0.22 max.	Nominal thickness > 30 mm
Si	0.55 max.	Standard heat-analysis limit
Mn	1.60 max.	Standard heat-analysis limit
P	0.025 max.	Standard heat-analysis limit
S	0.025 max.	Standard heat-analysis limit
Cu	0.55 max.	Standard heat-analysis limit
Deoxidation	FF	Fully killed; available nitrogen is to be bound
Other elements	Controlled by EN 10020 where not otherwise defined	The grade is not an unrestricted residual-element specification

These are heat-analysis requirements. Product analysis is a separate purchaser option and has its own permitted limits.

Maximum carbon equivalent value from heat analysis

Nominal product thickness (% CEV)	≤ 30 mm	> 30–40 mm	> 40–150 mm	> 150–250 mm	> 250–400 mm
Maximum carbon equivalent value from heat analysis	0.45	0.47	0.47	0.49	0.49

For long products over 150 mm through 250 mm, the maximum CEV is 0.54%. The >250–400 mm range is applicable to flat products.

IIW carbon-equivalent equation used by EN 10025-2

CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15

All elemental contents are mass percentages. CEV is a useful weldability indicator, but preheat and welding controls must also consider thickness, restraint, heat input and diffusible hydrogen.

S355J2 is routinely weldable using established procedures for structural steels, with EN 1011-2 providing the relevant European recommendations. Cold-cracking risk rises with increasing section thickness and restraint and results from the interaction of hydrogen, a susceptible heat-affected-zone microstructure and tensile stress. The mill certificate's actual composition and CEV should therefore be used when developing or confirming the welding procedure rather than relying only on the grade maximum.

Thickness-dependent tensile requirements

Minimum upper yield strength ReH at room temperature

Nominal thickness, mm (MPa)	≤ 16	> 16–40	> 40–63	> 63–80	> 80–100	> 100–150	> 150–200	> 200–250	> 250–400
Minimum upper yield strength ReH at room temperature	355	345	335	325	315	295	285	275	265

The >250–400 mm value applies to flat products. For irregular long-product sections, the thickness of the part from which the sample is taken governs.

Tensile-strength range Rm at room temperature

Nominal thickness (MPa)	< 3 mm	3–100 mm	> 100–150 mm	> 150–250 mm	> 250–400 mm
Tensile-strength range Rm at room temperature	510–680	470–630	450–600	450–600	450–600

The final range is for applicable flat products. Product-form limits still apply.

Minimum elongation after fracture for t ≥ 3 mm

Nominal thickness	Longitudinal A, min.	Transverse A, min.
3–40 mm	22%	20%
>40–63 mm	21%	19%
>63–100 mm	20%	18%
>100–150 mm	18%	18%
>150–250 mm	17%	17%
>250–400 mm	17%	17%

Gauge length L0 = 5.65√S0. Separate fixed-gauge elongation requirements apply below 3 mm.

For plate, sheet and wide flat of width at least 600 mm, the applicable tensile-test orientation is transverse to the rolling direction. For other products it is generally longitudinal. The inspection certificate should identify sample location and direction.

J2 impact toughness

Charpy V-notch requirement

Quality	Test-piece direction	Test temperature	Minimum energy
S355J2	Longitudinal	−20 °C	27 J
S355J2, reduced-width specimen	Longitudinal	−20 °C	Reduced in proportion to specimen cross-sectional area

The tabulated 27 J requirement applies through the applicable EN 10025-2 thickness ranges, subject to product-size and test-piece provisions.

J2 impact properties are verified by test unless otherwise agreed. Impact testing is not normally required where a test piece cannot be required under the dimensional rules: nominal thickness below 6 mm for flat products and sections, nominal diameter below 16 mm for round bars, or nominal thickness below 12 mm for rectangular bars and rod. For sections thicker than 100 mm, impact values are to be agreed using the relevant ordering option.

Routine verification is performed by the standard's inspection-unit rules, not automatically on every individual plate or coil. Where traceability to each parent plate or coil is important, EN 10025-2 provides options for impact testing alone or combined impact and tensile testing from each parent plate or coil.

Delivery condition and thermal processing

Permitted delivery conditions

Product route	Conditions permitted unless otherwise agreed	Practical point
Long products	Manufacturer may select +AR, +N or +M	Specify the required condition if subsequent processing or project rules make it important.
Hot-rolled strip and products from strip	Manufacturer may select +AR, +N or +M	Do not infer the condition from the grade name alone.
Quarto plate	Manufacturer may select +AR or +N	+M is not a permitted quarto-plate condition under this specification.
Condition explicitly ordered	Add +AR, +N or +M to the designation	The condition is also recorded on the inspection document.

EN 10025-2 applies the same tabulated mechanical requirements irrespective of the permitted delivery condition, but fabrication response can differ.

Only products ordered and supplied in the +N condition retain conformity with the specified mechanical tables after properly controlled hot forming or subsequent normalizing. Products in +AR or +M condition are not designated as suitable for hot forming under this rule. Incorrect high-temperature operations, including excessive flame straightening or rerolling, can reduce strength or toughness.

Stress relief above 580 °C or for more than one hour may deteriorate properties. For normalized or normalized-rolled flat products, EN 10025-2 recommends a maximum stress-relief temperature of 560 °C. If more severe treatment is intended, post-treatment mechanical requirements should be agreed with the producer before ordering.

Forming, galvanizing and other fabrication considerations

The basic S355J2 designation does not guarantee special cold-forming performance. Where flangeability, roll forming or cold drawing must be assured, the appropriate C-designated grade and the applicable EN 10025-2 option should be ordered. Cold forming reduces ductility and can be especially significant where heavily formed components will subsequently be galvanized.

For hot-dip galvanizing, coating requirements are specified through EN ISO 1461, while EN ISO 14713-2 addresses the influence of steel chemistry on coating formation. The broad S355J2 silicon limit does not by itself ensure a desired coating thickness or appearance. EN 10025-2 therefore provides an ordering option under which the purchaser and producer agree suitable silicon and phosphorus control.

The grade is machinable by conventional operations, but its relatively ductile chip may impair chip breaking or surface finish. A higher-sulfur or calcium-treated long-product variant may be available through a specific order agreement, but such material should not be assumed from the standard S355J2 name.

Ordering and certification points

Items to resolve on the purchase order

Order item	Why it matters
Product form and dimensions	The grade is supplied in multiple flat and long-product forms with different dimensional standards and thickness limits.
Full grade and delivery condition	Use, for example, EN 10025-2 S355J2+N when +N is mandatory; otherwise the producer may select among the permitted conditions.
Dimensional and shape-tolerance standard	Typical references include EN 10029 for quarto plate, EN 10051 for strip and cut-to-length products, and product-specific standards for sections and bars.
Inspection document under EN 10204	State the required document type; do not assume that the project-required certificate will be supplied automatically.
Impact-test scope	Consider parent-plate or parent-coil testing where routine inspection-unit testing is insufficient.
Product analysis	Heat analysis is standard; product analysis must be ordered using the applicable option if required.
Through-thickness ductility	Specify an EN 10164 Z-quality where lamellar-tearing resistance is required.
Internal soundness	Ultrasonic testing and acceptance class must be agreed; they are not inherent in S355J2.
Surface class and repair restrictions	Default surface classes apply unless a different class or tighter repair control is ordered.
Galvanizing chemistry	Specify the EN 10025-2 galvanizing option when predictable zinc-coating behavior is important.
Cold-forming suitability	Order the appropriate C designation and forming option rather than relying on ordinary S355J2.
Traceability and project documentation	Ensure heat identity, test orientation, test temperature, actual composition, CEV and delivery condition appear where required.

Plate tolerances default to EN 10029 thickness-tolerance class A unless otherwise agreed. Plate cut from continuously rolled strip normally follows EN 10051 unless an alternative is ordered.

Selection and substitution cautions

S355J2 is commonly selected when the room-temperature JR quality or 0 °C J0 quality does not provide the specified toughness test temperature. It remains a conventional non-alloy structural steel, not a fine-grain structural grade. S355N and S355M are governed by different parts of EN 10025 and have different chemistry, processing and property frameworks.

Cross-standard matches such as ASTM Grade 50 products should be treated only as possible engineering comparisons. Chemistry, CEV, thickness-dependent strength, impact testing, delivery condition, product route, tolerances and certification can differ. Substitution should be assessed against the complete purchase and design specification rather than nominal yield strength alone.

Sources

BS EN 10025-2:2019 — Hot rolled products of structural steels, Part 2: Technical delivery conditions for non-alloy structural steelsBritish Standards Institution
SIST EN 10025-2:2019 — Standard preview and technical clausesSlovenian Institute for Standardization / iTeh Standards
EN 10025-2:2019 — Hot rolled products of structural steels, Part 2UNI — Ente Italiano di Normazione
BS EN 10025-1:2004 — General technical delivery conditionsBritish Standards Institution
Declaration of Performance No. 1.0577 — S355J2 to EN 10025-2:2019Marcegaglia

ASK METALMATE

Ask MetalMate about S355J2

Discussing: S355J2 / 1.0577

AI assistant · Responses are generated and can contain errors; verify specifications before acting.

S355J2+N / 1.0577+N	Same EN 10025-2 grade with normalized or normalized-rolled condition explicitly specified	Useful where controlled hot forming, subsequent normalizing or greater thermal-processing robustness is required.
S355JR / 1.0045	Related S355 quality	Minimum Charpy energy is associated with a higher test temperature than J2; it is not a toughness-equivalent substitute.
S355J0 / 1.0553	Related S355 quality	Specifies 27 J at 0 °C rather than −20 °C.
S355K2 / 1.0596	Higher-toughness quality in the same EN 10025-2 family	Impact-energy requirements differ and remain thickness-dependent.
S355J2C / 1.0579	Cold-forming variant related to S355J2	Use when the applicable EN 10025-2 cold-forming option and C designation are required.
S355J2H	Related hollow-section designation	Governed by EN 10210 or EN 10219 as applicable; it is not the same product specification as EN 10025-2 S355J2.
St 52-3 and S355J2G3/G4	Historical predecessor designations	Legacy material should not be accepted solely by name comparison; confirm the original standard edition, condition, impact testing and certification.