Structural steel#Structural shapes

Most steels used in Europe are specified to comply with EN 10025. However, some national standards remain in force.{{Cite web|url=https://jsplstructurals.com/|title=Structurals | Structure Steel | Structural Steel by JSP Structurals|date=March 17, 2023}} Example grades are S275J2 or S355K2W where S denotes structural steel; 275 or 355 denotes the yield strength in newtons per square millimetre or the equivalent megapascals; J2 or K2 denotes the material's toughness by Charpy impact test values, and the W denotes weathering steel. Further letters can be used to designate fine grain steel (N or NL); quenched and tempered steel (Q or QL); and thermomechanically rolled steel (M or ML).{{cn|date=March 2025}}

Common yield strengths available are 195, 235, 275, 355, 420, and 460, although some grades are more commonly used than others. In the UK, almost all structural steel is S275 and S355. Higher grades such as 500, 550, 620, 690, 890 and 960 available in quenched and tempered material although grades above 690 receive little if any use in construction at present.{{cn|date=March 2025}}

Euronorms define the shape of standard structural profiles:

• European I-beam: IPE – Euronorm 19-57
• European I-beam: IPN – DIN 1025-1
• European flange beams: HE – Euronorm 53-62
• European channels: UPN – DIN 1026-1
• European cold formed IS IS 800-1{{cn|date=March 2025}}

Steels used for building construction in the US use standard alloys identified and specified by ASTM International. These steels have an alloy identification beginning with A and then two, three, or four numbers. The four-number AISI steel grades commonly used for mechanical engineering, machines, and vehicles are a completely different specification series.

The standard commonly used structural steels are:Manual of Steel Construction, 8th Edition, 2nd revised printing, American Institute of Steel Construction, 1987, ch 1 page 1-5

• A36 – structural shapes and plate.
• A53 – structural pipe and tubing.
• A500 – structural pipe and tubing.
• A501 – structural pipe and tubing.
• A529 – structural shapes and plate.
• A1085 – structural pipe and tubing.

• A441 – structural shapes and plates (Superseded by A572)
• A572 – structural shapes and plates.
• A618 – structural pipe and tubing.
• A992 – Possible applications are W or S I-Beams.
• A913 – Quenched and Self Tempered (QST) W shapes.
• A270 – structural shapes and plates.

• A243 – structural shapes and plates.
• A588 – structural shapes and plates.

• A514 – structural shapes and plates.
• A517 – boilers and pressure vessels.
• Eglin steel – Inexpensive aerospace and weaponry items.

• A668 – Steel Forgings

File:Non-preload bolt assembly (EN 15048).png

File:EN 14399 Pre-load bolt assembly (System HR).png

The concept of CE marking for all construction products and steel products is introduced by the Construction Products Directive (CPD). The CPD is a European Directive that ensures the free movement of all construction products within the European Union.

Because steel components are "safety critical", CE Marking is not allowed unless the Factory Production Control (FPC) system under which they are produced has been assessed by a suitable certification body that has been approved to the European Commission.The website of the British Constructional Steelwork Association. – SteelConstruction.org:CE-Marking.08/02/2011.

In the case of steel products such as sections, bolts and fabricated steelwork the CE Marking demonstrates that the product complies with the relevant harmonized standard.Guide to the CE Marking of Structural Steelwork, BCSA Publication No. 46/08. p.1.

For steel structures the main harmonized standards are:

• Steel sections and plate – EN 10025-1
• Hollow sections – EN 10219-1 and EN 10210-1
• Pre-loadable bolts – EN 14399-1
• Non-preloadable bolts – EN 15048-1
• Fabricated steel – EN 1090 −1

The standard that covers CE Marking of structural steelwork is EN 1090-1. The standard has come into force in late 2010. After a transition period of two years, CE Marking will become mandatory in most European Countries sometime early in 2012.[http://www.tuv.com/en/corporate/business_customers/construction_real_estate/building_materials/manufacturer_certification_en1090/manufacturer_certification_en1090.jsp?null Manufacturer Certification in Compliance with EN 1090], 09.08.2011 The official end date of the transition period is July 1, 2014

Steel is sold by weight so the design must be as light as possible whilst being structurally safe. Utilizing multiple, identical steel members can be cheaper than unique components.{{cite book|last=Popescu|first=Calin|title=Estimating Building Costs}}

Reinforced concrete and structural steel can be sustainable{{cite web |title=The Environmental Impact of Steel |date=15 December 2020 |url=https://www.metsec.com/the-environmental-impact-of-steel/ |publisher=voelstapine Metsec|language=English}} if used properly. Over 80% of structural steel members are fabricated from recycled metals, called A992 steel. This member material is cheaper and has a higher strength to weight ratio than previously used steel members (A36 grade).{{cite book|last=Zaharia|first=Raul|title=Designing Steel Structures for Fire Safety|isbn=978-0-415-54828-1|date=2009-05-06|publisher=Taylor & Francis }}

Special considerations must be taken into account with structural steel to ensure it is not under a dangerous fire hazard condition.{{cite book|title=Handbook of Structural Engineering|year=1997|publisher=CRC Press|isbn=978-0-8493-2674-5}}

Structural steel cannot be exposed to the environment without suitable protection, because any moisture, or contact with water, will cause oxidisation to occur, compromising the structural integrity of the building and endangering occupants and neighbors.

Having high strength, stiffness, toughness, and ductile properties, structural steel is one of the most commonly used materials in commercial and industrial building construction.{{cite book|last=Chen|first=Wai-Fah|title=Principles of Structural Design|year=2005|publisher=Taylor & Francis |isbn=978-0-8493-7235-3}}

Structural steel can be developed into nearly any shape, which are either bolted or welded together in construction. Structural steel can be erected as soon as the materials are delivered on site, whereas concrete must be cured at least 1–2 weeks after pouring before construction can continue, making steel a schedule-friendly construction material.

Steel is inherently a noncombustible material. However, when heated to temperatures seen in a fire, the strength and stiffness of the material is significantly reduced. The International Building Code requires steel be enveloped in sufficient fire-resistant materials, increasing overall cost of [https://paradigm-structural.com/services/structural-design/ steel structure] buildings.

Steel, when in contact with water, can corrode, creating a potentially dangerous structure. Measures must be taken in structural steel construction to prevent any lifetime corrosion. The steel can be painted, providing water resistance. Also, the fire resistance material used to envelope steel is commonly water resistant.

Steel provides a less suitable surface environment for mold to grow than wood.{{cite web | url=http://www.absoluterv.com/help-and-resources/steel_building_benefits/properties-prevention-household-mold/ | title=Properties and Prevention of Household Mold | publisher=Absolute Steel | date=7 March 2014 | access-date=2 November 2014 | author=Armstrong, Robert | archive-date=6 October 2014 | archive-url=https://web.archive.org/web/20141006082445/http://www.absoluterv.com/help-and-resources/steel_building_benefits/properties-prevention-household-mold/ | url-status=dead }}

Tall structures are constructed using structural steel due to its constructability, as well as its high strength-to-weight ratio.{{cite book|last=Taranath|first=Bungale|title=Reinforced Concrete Design of Tall Buildings|isbn=978-1-4398-0480-3|date=2009-12-14|publisher=Taylor & Francis }}

File:Owsj deck fireproofing.jpg-leavened gypsum]]

Steel loses strength when heated sufficiently. The critical temperature of a steel member is the temperature at which it cannot safely support its load {{Citation needed|date=June 2024}}. Building codes and structural engineering standard practice defines different critical temperatures depending on the structural element type, configuration, orientation, and loading characteristics. The critical temperature is often considered the temperature at which its yield stress has been reduced to 60% of the room temperature yield stress.Industrial fire protection engineering, Robert G. Zalosh, copyright 2003 pg.58 In order to determine the fire resistance rating of a steel member, accepted calculations practice can be used,Zalosh, Pg. 70 or a fire test can be performed, the critical temperature of which is set by the standard accepted to the Authority Having Jurisdiction, such as a building code. In Japan, this is below 400 °C.{{Cite journal |last=Shigekura |first=Yuko |title=FIRE RATING PROCEDURE IN JAPAN |url=https://publications.iafss.org/publications/aofst/1/60/view/aofst_1-60.pdf |journal=International Association for Fire Safety Science}} In China, Europe and North America (e.g., ASTM E-119), this is approximately 1000–1300 °FZalosh, Table 3.3 (530–810 °C). The time it takes for the steel element that is being tested to reach the temperature set by the test standard determines the duration of the fire-resistance rating.

Heat transfer to the steel can be slowed by the use of fireproofing materials, thus limiting steel temperature. Common fireproofing methods for structural steel include intumescent, endothermic, and plaster coatings as well as drywall, calcium silicate cladding, and mineral wool insulating blankets.Best Practice Guidelines for Structural Fire Resistance Design of Concrete and Steel Buildings, NIST Technical Note 1681, L. T. Phan, J. L. Gross, and T. P. McAllister, 2010. [https://dx.doi.org/10.6028/NIST.TN.1681 (View report)]

Structural steel fireproofing materials include intumescent, endothermic and plaster coatings as well as drywall, calcium silicate cladding, and mineral or high temperature insulation wool blankets. Attention is given to connections, as the thermal expansion of structural elements can compromise fire-resistance rated assemblies.

Cutting workpieces to length is usually done with a bandsaw.{{Citation needed|date=August 2018}}

A beam drill line drills holes and mills slots into beams, channels and HSS elements. CNC beam drill lines are typically equipped with feed conveyors and position sensors to move the element into position for drilling, plus probing capability to determine the precise location where the hole or slot is to be cut.{{cn|date=March 2025}}

For cutting irregular openings or non-uniform ends on dimensional (non-plate) elements, a cutting torch is typically used. Oxy-fuel torches are the most common technology and range from simple hand-held torches to automated CNC coping machines that move the torch head around the structural element in accordance with cutting instructions programmed into the machine.{{cn|date=March 2025}}

Fabricating flat plate is performed on a plate processing center where the plate is laid flat on a stationary 'table' and different cutting heads traverse the plate from a gantry-style arm or "bridge". The cutting heads can include a punch, drill or torch.{{cn|date=March 2025}}

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• Steel frame
• Steel design
• Structural engineering

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{{Commons category|Structural_steel|Structural Steel}}

• [https://www.webarchive.org.uk/wayback/archive/20110412222959/http://www.steelconstruction.org/images/stories/ce_book_final1.pdf Guide to the CE Marking of Structural Steelwork, BCSA Publication No. 46/08.]
• [http://www.steelconstruction.info Steel Construction Info] from the British Constructional Steelwork Association
• [https://www.aisc.org/globalassets/aisc/publications/historic-shape-references/hot-rolled-carbon-steel-structural-shapes-1948.pdf Structural Steel Handbook]
• [https://www.staticstools.eu Technical data about most common European structural shapes]

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