In most developed countries, the shapes available are set out in published standards, although a number of specialist and proprietary cross sections are also available.
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) 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)
Channel (C-shaped 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 or wood, see also rebar and dowel.
Plate, sheet metal 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).
Please check following sketchs for some reference of how the parts been installed with the structures.