Structural steel is a category of steel used for making construction materials in a variety of shapes. Many structural steel shapes take the form of an elongated beam having a profile of a specific cross section. Structural steel shapes, sizes, chemical composition, mechanical properties such as strengths, storage practices, etc., are regulated by standards in most industrialized countries.
Most structural steel shapes, such as I-beams, have high second moments of area, which means they are very stiff in respect to their cross-sectional area and thus can support a high load without excessive sagging.
Common structural shapes
The shapes available are described in many published standards worldwide, and a number of specialist and proprietary cross sections are also available.
A steel I-beam, in this case used to support timber joists in a house.
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB) and Universal Columns (UC); in Europe it includes the IPE, HE, HL, HD and other sections; in the US it includes Wide Flange (WF or W-Shape) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow section) and including square, rectangular, circular (pipe) and elliptical cross sections)
Angle (L-shaped cross-section)
Structural channel, or C-beam, or C cross-section
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar, a piece of metal, rectangular cross sectioned (flat) and long, but not so wide so as to be called a sheet.
Rod, a round or square and long piece of metal, see also rebar and dowel.
Plate, metal sheets thicker than 6 mm or 1⁄4 in.
Open web steel joist
While many sections are made by hot or cold rolling, others are made by welding together flat or bent plates (for example, the largest circular hollow sections are made from flat plate bent into a circle and seam-welded)
Standards
A set of Euronorms define the shape of a set 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
Standard structural steels (USA)
Carbon steels
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.
High strength low alloy steels
A441 - structural shapes and plates.
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.
A521 - structural plates
Corrosion resistant high strength low alloy steels
A243 - structural shapes and plates.
A588 - structural shapes and plates.
Quenched and tempered alloy steels
A514 - structural shapes and plates.
A517 - boilers and pressure vessels.
Eglin steel - Inexpensive aerospace and weaponry items.
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
Manufacturing
Cutting workpieces to length is usually done with a bandsaw.
A beam drill line (drill line) has long been considered an indispensable way to drill holes and mill 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.
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.
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.
