Editorial Feature

Structural Steel - S235, S275, S355 Chemical Composition, Mechanical Properties and Common Applications

Structural steel is a standard construction material made from specific grades of steel and formed in a range of industry-standard cross-sectional shapes (or ‘Sections’). Structural steel grades are designed with specific chemical compositions and mechanical properties formulated for particular applications.

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In Europe, structural steel must comply with the European Standard EN 10025, which is governed by the European Committee for Iron and Steel Standardization (ECISS), a subset of the European Committee for Standardization (CEN).

There are many examples of European grades of structural steel – for example, S195, S235, S275, S355, S420, and S460. For the purposes of this article, we will focus on the chemical composition, mechanical properties, and applications of S235, S275, and S355, which are three common structural steel grades used in all manner of construction projects across the EU.

In line with the European Standard classifications, structural steels must be referenced using standard symbols including but not limited to S, 235, J2, K2, C, Z, W, JR, and JO, where:

  • ‘S’ denotes the fact that it is structural steel;
  • ‘235’ which relates to the minimum yield strength of the steel (tested at a thickness of 16mm);
  • ‘J2’, ‘K2’, ‘JR’, and ‘JO’ all demonstrate the material toughness in relation to the Charpy impact or ‘V’ notch test methodology;
  • ‘W’ is weathering steel (atmospheric corrosion-resistant);
  • ‘Z’ represents structural steel with improved strength perpendicular to the surface, and
  • ‘C’ is cold-formed.

Depending on the manufacturing process, chemical composition and relevant application, further letters and classifications might be used to reference particular grades or products of structural steel.

The EU standard classifications are not a global standard and therefore a number of corresponding grades with the same chemical and mechanical properties may be used in other parts of the world. For example, structural steels fabricated for the US market must be specified in accordance with the American Society for Testing and Materials (ASTM). International guidelines are referenced with an ‘A’ and then the relevant grade, for example, A36 or A53.

EU and US Equivalent Grades









In most countries, structural steel is regulated and must meet a minimum specific criterion for shape, size, chemical composition and strength.

The chemical composition of structural steel is extremely important and highly regulated. It is a fundamental factor which defines the mechanical properties of the steel. In the following table, you can see the maximum percentage levels of certain regulated elements present in European structural steel grades S235, S275, and S355.

Chemical Composition of Structural Steels - S235, S275 and S355

The Chemical composition of Structural Steel is extremely important and highly regulated. It is a fundamental factor which defines the Mechanical properties of the steel material. In the following table you can see the Max % levels of certain regulated elements present in European Structural steel grades S235, S275 and S355.

EU Grade







0.22 max

1.60 max

0.05 max

0.05 max

0.05 max


0.25 max

1.60 max

0.04 max

0.05 max

0.05 max


0.23 max

1.60 max

0.05 max

0.05 max

0.05 max

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The chemical composition of structural steel is incredibly important to the engineer and will change with specific grades depending on their intended use. For example, S355K2W is a structural steel that has been hardened, denoted by K2, and has been designed with a chemical composition to withstand increased weathering - W. Therefore, this grade of structural steel will have a slightly different chemical composition to the standard S355 grade.

Mechanical Properties of Structural Steel - S235, S275, S355

The mechanical properties of structural steel are fundamental to its classification and application. Even though chemical composition is a dominant factor in determining the mechanical properties of steel, it is also very important to understand the minimum standards for the mechanical properties or performance characteristics, such as yield strength and tensile strength, which are described in more detail below.

Yield Strength

The yield strength of structural steel measures the minimum force required to create a permanent deformation in the steel. The naming convention used in European Standard EN10025 refers to the minimum yield strength of the steel grade tested at 16mm thick.

Structural Steel Grade at 16mm

Minimum Yield Strength at nominal thickness 16mm


N/mm2 (MPa)


33 000

235 N/mm2


36 000

275 N/mm2


50 000

355 N/mm2

Tensile Strength

The Tensile Strength of structural steel relates to the point at which permanent deformation occurs when the material is pulled or stretched laterally along its length.

Structural Steel Grade

Tensile Strength MPa at Nom thickness between 3mm and 16mm


360 – 510 MPa


370 – 530 MPa


470 – 630 MPa

Typical Structural Steel ‘Sections’ / Cross-Sectional Shapes

Structural steel comes in many grades but is normally sold pre-formed with a defined cross-sectional shape, designed for specific applications. For example, it is common to find structural steel sold in I-beams, Z-beams, box lintels, hollow structural section (HSS), L-shaped and steel plate.

Depending on the desired application, an engineer will specify a grade of steel -usually to meet minimum strength, maximum weight and possibly weathering requirements, as well as the sectional shape - relative to the desired location and expected load to be carried or job to be performed.

Applications of Structural Steel

Structural steels are used in many ways and their application can be diverse. They are particularly useful because they offer the unique combination of good welding properties with guaranteed strengths. Structural steel is an extremely adaptable product and is often favored by engineers trying to maximize strength or ‘S’ structure while minimizing its weight.

It will come as no surprise that the construction industry is the biggest consumer of structural steel, where it is used for a number of purposes. Whether a small box lintel is used to carry the load of a structural wall in a residential property or a vast I-beam is bolted in place to hold the road surface on a bridge, structural steel can be specified, designed and fabricated for any type of job.

This information has been sourced, reviewed and adapted from materials provided by Masteel UK Ltd.

For more information on this source, please visit Masteel UK Ltd.

This article was updated on 7th August, 2019.


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  1. Kashif Khawaja Kashif Khawaja United States says:

    How can I calculate the yield strength suitable for my load?

    e.g for HEA 340 what yield strength is sufficient to carry 5 ton moving crane?

    • Paul Murphy Paul Murphy United Kingdom says:

      Hi Kashif,

      I unfortunately cannot give you a definitive answer. You would have to contact somebody that has access to a load cell programme i.e. an architect or someone who offer finite element analysis.

      The highest grade available from stock is 355N/mm yield at this size though.

      If you require any further information please contact [email protected]

  2. sujil suji sujil suji Malaysia says:

    Dear Sir,
                  How can I get the P no of this S275  Steel

    • Paul Murphy Paul Murphy United Kingdom says:

      Dear Sujil,

      Are you referring to Phosphorus level of S275 or are you referring to the Pressure application equivalent (P275)?

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      P chemical content of s275 is 0.016. before we test result

  3. Rahul Pratap Rahul Pratap India says:


    • Ramesh Kannan Ramesh Kannan Singapore says:

      Please can you any one advise my WPS is Qualified AWS D1.1 5-unlimited with charpy and without charpy...group II Material Gr X52...can use 355 Material this WPS?

      • Biju Abraham Biju Abraham India says:

        Is steel gare S275 is equivelant to ASTM A 36

        • nabil muslem nabil muslem Iraq says:

          S275 is equivelant to A570Gr40

  4. Andrew Collinson Andrew Collinson United Kingdom says:

    Is there any simple field test for determining if steelwork is S275 or S355?

    • Paul Murphy Paul Murphy United Kingdom says:

      Hi Andrew,

      The only field test I believe you can be referring to is a PMI test.

      It's a non-destructive spectrographic chemical analysis.

      It won't determine which grade it is but might prove it can't be S355.

      Hope that makes sense.

      Kind Regards,
      Paul Murphy (Masteel UK Ltd)

  5. Suresh Surendran Suresh Surendran U.A.E. says:

    can 275 and 355 grade welded using the same wps

  6. Suraj Ranaweera Suraj Ranaweera Sri Lanka says:

    can you tell me what can we use as alternative steel for S355.. Japanees Chinese & American please

    • Edir Thamrin Edir Thamrin Malaysia says:

      EH36 or ASTM A572 Gr50

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      chinese is q345/q355b

  7. sumeet malik sumeet malik India says:

    What is the difference between S355H and S355N/H. Is there any difference in yield strength values?

  8. emeline marteja emeline marteja Jordan says:

    My client required  ASTM A283GR C Group 1,, we offered S275 JR for Steel Flat Bar. Is it ok for them to use S275 JR as an alternative.  We don't have A283 GR C in stock right now.  Please assist.

    • Nouraldin Yousef Nouraldin Yousef Egypt says:

      Did you find the best solution sir,, was s275  accepted as an alternative please assist
      As I am facing the same situation right now

    • Iain Crawford Iain Crawford United Kingdom says:

      As long as the geometrical properties are the same for both, the S275 is a better grade of steel.

  9. Arun Kuttikkattu Vijayan Arun Kuttikkattu Vijayan U.A.E. says:

    What is the equivalent grade of S275 in american standard?

    • Paul Murphy Paul Murphy United Kingdom says:


      Closest American equivalent would be either ASTM A36 or A283 GR C

      • Iain Crawford Iain Crawford United Kingdom says:

        Really? the above table says that A283C is S235. S275 is A570GR40. am I missing something?

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      astm a36

  10. Ashraf Asagifi Ashraf Asagifi Libya says:

    I'd like to say : thanks , could you possibly   sending me the source of this article or any official related to ?? , the best article , I've ever read .
    thank you again .

  11. Shridhar Rai Shridhar Rai India says:

    Is E250 BR is equivalent to S275?

  12. Amira El Ayeb Amira El Ayeb Tunisia says:

    Hey , How can i find this material in Solidworks ?

    • Ashraf Asagifi Ashraf Asagifi Libya says:

      Amira are you steel strcture engineer


      you can only find different pure forms of alloys like mild steel , with density 7850 and yst 210 ,but you cant get through different grades of steel .

  13. Imran Zada Imran Zada Islamic Republic of Pakistan says:

    the values of yield strength is not in ksi,like given . Please make correction it should be   33 000 psi for S235 instead of  33000 ksi.

  14. Didik Setiono Didik Setiono Indonesia says:

    Dear Sir,
    Did S235 J2 equivalent with A333 Gr6 or A36 ???
    And S355 J2 equivalent with A572 Gr.50 ???

    Thanks for your attention
    Didik S

    • Paul Murphy Paul Murphy United Kingdom says:

      Hello Didik,

      Generally speaking S235 will not be certified as S235J2 you would tend to see this grade certified in S235JR with a EN10204 2.2 certificate. This grade is not interchangeable with A333 GR 6 (pipe specification) or ASTM A36 (Sheet/plate & structural sections specification).

      The EN equivalent of ASTM A36 would be S275JR.

      S355J2+N/M is the direct EN equivalent of ASTM A572 GR 50.

      Hope this helps.

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      yes,they are match.

  15. Tracy Kearney Tracy Kearney Ireland says:

    I am designing using S275 grade steel but I understand that there is no cost difference between the S275 and S355. Is this correct? Is S275 an obsolete grade?

    • Paul Murphy Paul Murphy United Kingdom says:

      Hi Tracy,

      I'm afraid the information you have is incorrect. S275 is not an obsolete grade and is still a mainstay in the construction industry perhaps even more so than S355 material.

      S355 is a higher grade of material compared to S275 and therefore there is a cost difference between the two grades.

      Hope this helps.

      Paul Murphy

      • Apex Cary Apex Cary India says:

        we are using both S235JR and S355J2+N

        can you pl confirm what is 'N'?


        • A M A M India says:

          Normalized steel process

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      no, they are different cost, s355 is higher

  16. P K Unnikrishnan P K Unnikrishnan India says:

    In the chemical composition of steel what is W stands for

  17. Subho Chatterjee Subho Chatterjee India says:


  18. Pushparaj P.V. Pushparaj P.V. U.A.E. says:

    Can I use the ASTM E570 instead of S275JR for handrails. Which one is the higher grade.

  19. Stephen Taylor Stephen Taylor United Kingdom says:

    is S355NLW Grade Structural Steel readily available in UK

  20. Muhammad Farhan Muhammad Farhan Portugal says:

    What is the approximate cost of steel grade S355 and S690?

  21. E. Nussbacher E. Nussbacher Belgium says:

    One of our contractors claims that S235 is the standard material used for most industrial steel profiles ans if one wants S355 - it will require a special order with long lead times.
    Is this correct?


      yes ,

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      yes, s355 is higer strength.

  22. Chellam Muniyandi Chellam Muniyandi Kuwait says:

    Anybody help me provide the chemical & Physical properties of BS:4592-5 Steel plate for floor purpose...

  23. Chellam Muniyandi Chellam Muniyandi Kuwait says:

    I need chemical & physical properties of BS:4592-5 ....Anybody possible to help?

  24. Hamdi Ismail Hamdi Ismail Malaysia says:


    - S355 grade need to preheat before welding process? if Yes, what is the preheat temperature and how long to preheat?  how many % the strength reduce (S355 grade) for built up plate / after preheat?

  25. Keshav Bhojwani Keshav Bhojwani Curaçao says:

    Hi, I am trying to order a steel structure that is approx 11m high and has 2 stories (ground floor and 2nd floor) . i am getting an offer from Europer (more reliable) for S235JR steel and one from china for s355JR (Q345B) steel. The second floor is warehousing and needs to hold a lot of weight. A pallet that we have (for example) weighs over 800kgs. the chinese factore claims that S235JR is NOT sufficiently strong to hold this kind of weight and the steel construction HAS to be S355JR, while the European company claims different. the structure is 27m wide by 36m long and the columns are 9m and 6m apart respectivly on the ground floor and the second floor is freespan all the way. does anyone have any advise what steel would be best suited for this project?

    thank you!

    • A M A M India says:



      as 355 denote yst

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      s355 is more equal.

  26. Jeri Cadi Jeri Cadi Philippines says:

    can S355 be welded in A36 steel?

    • Chen Ada Chen Ada Hong Kong S.A.R. says:


  27. Jeri Cadi Jeri Cadi Philippines says:

    can S355 be welded to A36 steel? What is the recommended welding process/method?

  28. Ritchie Hutton Ritchie Hutton United Kingdom says:

    We had material supplied via a Russian mill as grade S235. When we tested it with an independant UKAS testing facility the yield and tensile closely matchedthat of S355. Can we request that the material be upgraded to S355 and request a re-issue of the mill certs?

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      s355 is different with s235. the strength is much higher than s235 common

  29. Abdallah Aschkar Abdallah Aschkar Ghana says:

    I am constructing a vertical tank from S235JR steel, and I would like to know wether I can use S275JR steel for an accessory, namely the  windgirder at the top
    The question is are the two types of steel weldable together? The electrode I am using on site is of grade ER 7018

  30. Hafsa Byah Hafsa Byah Morocco says:

    does anyone have any advise what steel would be besT

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      china steel grade q345b is enough.

  31. Pradip Manekar Pradip Manekar Bahrain says:

    I need to ask the S275 grade ---if not available, then can we use C22 grade materials.

  32. Robert Emrys Long Robert Emrys Long Denmark says:

    corrosion, is there a difference between the corrosion in salt water of S 235 and S355
    where can i find documentation


    what is the meaning of b at the end of S235 JRB

  34. Muhammad Muslim Muhammad Muslim Islamic Republic of Pakistan says:

    dear all can anyone send me (S235) materail PQR and wps at
    [email protected]

  35. MUDD SID MUDD SID Islamic Republic of Pakistan says:

    I need to ask the S235 grade ---if not available, then can we use A36 grade materials.

  36. MARTIN HOSSAIN MARTIN HOSSAIN Trinidad and Tobago says:

    what type of steel mat'l is -- S355 compatable to, mild steel, en19, want to make sleeve spacers for tightening bolts, and does this S355 comes in round stock shaft mat'l

  37. Senad Kudumović Senad Kudumović Sweden says:


    I would like to know more about content of Co (cobalt) and Ni (nickel) in S355, since that is not stated in chemical properties table? Can you please provide that?
    Reason for that is because the plan is to use this material in nuclear facility.

  38. Wahid m. Wahid m. U.A.E. says:

    Is S275JR is equivalent to S355?

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      no,s235 is ok. s355 is higher strength than s275 and s235.

  39. Brett Williams Brett Williams South Africa says:

    I've been advised to use 1026 for a suspension system but all I can source in South Africa is S355. Is this equivalent, better, worse?




    How i can select a steel
    1) with low tensile strength and high ductility
    2) High tensile strength and low ductility

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      how much do you want indeed?

  41. ofir benyamin ofir benyamin Israel says:

    what is the approximately yield stress for a S355 STEEL with corrosion, is there any data about it?

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      s355 yield strength about 424mpa.


    cost of beam for anchorage S355 GP EN10248-1

  43. Bryony Coleman Bryony Coleman United Kingdom says:

    I am looking for a UK equivalent to Fe 490-2 to comply with BS EN standard, can you help? please

  44. Ehsan Al Lawati Ehsan Al Lawati India says:

    I have 3 different sizes of steel plates with following specs which have gone through a Charpy Test (3 specimens for each, below I will put average results). How do I know that those three sized plates have succeeded and passed the test? What are the criteria/ parameters that I need to check against?

    Plate 1: S275JR, sample 200x200x30mm thickness (specimen dimensions 10x10x55 mm), Charpy Test Impact (0 degrees Temp) Average result 305, Orientation Transverse

    Plate 2: S275JR, sample 200x200x20mm thickness (specimen dimensions 10x10x55 mm), Charpy Test Impact (0 degrees Temp) Average result 159, Orientation Transverse

    Plate 3: S275JR, sample 200x200x16mm thickness (specimen dimensions 10x10x55 mm), Charpy Test Impact (0 degrees Temp) Average result 187, Orientation Transverse

  45. Pallab Dutta Pallab Dutta U.A.E. says:

    I am stuck in a position where I need some help of expert like you. As per subjected standard table -1, nitrogen %, max 0.012 allowable for grade S355JR, but mill supplied material with 0.013% nitrogen and they are showing cause of acceptance as per footnote ‘f’ of table 1.

    My query :
    1.  “The max, value for nitrogen does not apply” – is this mean, any value can be acceptable, if other part of the note satisfied?
    2.  AL content is not as per required value in this case, but they are arguing about ‘sufficient’ other N binding element, like V, Nb, Cr etc., but my query is, what is the ‘sufficient’  amount of other N binding element? Because it is not clear in standard.

  46. Naveed Zafar Naveed Zafar Islamic Republic of Pakistan says:

    S275JR would be equivalent to ASTM A36???

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      mostly yes,

  47. Vellai C Vellai C U.A.E. says:

    can we weld the S355 steel to S275 grade steel?

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      yes,they can.

  48. Vishnu Chandralal Vishnu Chandralal U.A.E. says:

    “For materials S355JR temperature stands for +20 as per code
    For minus (-) temperature without impact need to use S355J2 & S355K2 endure up to -20 degrees.
    Please confirm if S355JR materials will endure the cold temperature environment of -6 to -2 degrees daily all year round. If not then up to what temperature S355JR materials will have no impact.”

  49. a g a g Kazakhstan says:

    Hello Experts, Can you please advise how to determine , if S420 G2M is group III as per AWS D1.1 ,

    Thank you  .

  50. Anis Mohabeddine Anis Mohabeddine Portugal says:

    Can you tell me what is the difference between S275 and S235? they have very close mechanical properties

  51. Ajay Joshi Ajay Joshi India says:

    Whats stands for'F' in steel grade S235jrF?

  52. D. Jey D. Jey U.A.E. says:

    I would like to know specific application of the carbon steel S355 for welding purpose (for example: chassis of any car, welding of dissimilar metals etc)

  53. azin yazdi azin yazdi Denmark says:

    calculation for S275JR is done without taking 1 mm corrosion allowance in to consideration, is there any way to compensate this in material strength by cladding or...? any advise is highly appreciated.

  54. Babu R Babu R India says:

    thanks for the article details.
    when someone agrees to supply YST 355 Grade steel then would it be a genuine>
    alternatively, not sure if chemical composition certificate would be sufficient. Can you help me. NEED Help pl.

  55. Banny Lau Banny Lau Japan says:

    Hi All, What kind of steel is good for making an 1100 liters hydraulic oil tank? how about carbon steel S275?
    please guide me.
    Thank you.

  56. Ahmed Diab Ahmed Diab Egypt says:

    What is the minimum dimensions for S355J2 Steel sample to do mill test certificate

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      in common 300*300mm is enough.


    Hello Everybody, please I ahve a question, can this material S235 used for heat resistant it equivalent to 16MO3, I need to use it for aclinker cooler in cement

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      no, heat resistant need alloy.

  58. Nguyen Dang Minh Duong Nguyen Dang Minh Duong Lao P.D.R. says:

    I want to know the yield strength, tensile strength and elongation of HEB160, HEB180 grade S235JR.

    • Chen Ada Chen Ada Hong Kong S.A.R. says:

      in common yield strength is 326,tensile: 471. elongation:32.

  59. Hassan eltob Hassan eltob Egypt says:

    Could steel JR substitute J0? and why?

  60. Jacob Neil Jacob Neil United States says:

    Is one grade of HR more suitable for galvanizing than another? Related, what is the difference between Class 1 and Class 3 galvanizing? What would make what grade more suitable for each Class? Thank you

  61. Brave Heart Brave Heart Islamic Republic of Pakistan says:

    Sir is S355K2G3 and S355K2 are same material or have any difference?
    Kashif Mehmood

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of AZoM.com.

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