Structural Steel

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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. S45c Steel Pipe

Structural Steel

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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:

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.

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.

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.

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.

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.

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

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.

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

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.

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.

Please use one of the following formats to cite this article in your essay, paper or report:

Gilbert, Nick. (2023, April 27). Structural Steel - S235, S275, S355 Chemical Composition, Mechanical Properties and Common Applications. AZoM. Retrieved on September 27, 2023 from

Gilbert, Nick. "Structural Steel - S235, S275, S355 Chemical Composition, Mechanical Properties and Common Applications". AZoM. 27 September 2023. <>.

Gilbert, Nick. "Structural Steel - S235, S275, S355 Chemical Composition, Mechanical Properties and Common Applications". AZoM. (accessed September 27, 2023).

Gilbert, Nick. 2023. Structural Steel - S235, S275, S355 Chemical Composition, Mechanical Properties and Common Applications. AZoM, viewed 27 September 2023,

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?

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]

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

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

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


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

Is steel gare S275 is equivelant to ASTM A 36

no S275 is equivelant to A570Gr40

Hi, Is there any simple field test for determining if steelwork is S275 or S355? Thanks Andrew

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)

can 275 and 355 grade welded using the same wps

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

EH36 or ASTM A572 Gr50

chinese is q345/q355b

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

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.

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

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

What is the equivalent grade of S275 in american standard?

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

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

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 .

Is E250 BR is equivalent to S275?

Hey , How can i find this material in Solidworks ?

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 .

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.

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

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.

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?

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

Yes we are using both S235JR and S355J2+N can you pl confirm what is 'N'? Thanks

no, they are different cost, s355 is higher

In the chemical composition of steel what is W stands for


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

is S355NLW Grade Structural Steel readily available in UK

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

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, s355 is higer strength.

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

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

Hi, - 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?

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!

can S355 be welded in A36 steel?

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

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?

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

Hello 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

I NEED INORMATION USE  OF S355 IN MARINE STRUCTURES does anyone have any advise what steel would be besT

china steel grade q345b is enough.

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

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

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

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

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

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

Hi, 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. Thanks.

Is S275JR is equivalent to S355?

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

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? Thanks, Brett

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

how much do you want indeed?

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

s355 yield strength about 424mpa.

cost of beam for anchorage S355 GP EN10248-1

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

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

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.

S275JR would be equivalent to ASTM A36???

can we weld the S355 steel to S275 grade steel?

“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.”

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

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

Whats stands for'F' in steel grade S235jrF?

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)

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.

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.

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.

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

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

no, heat resistant need alloy.

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

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

Could steel JR substitute J0? and why?

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

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