I-beams, as the name states are manufactured in the shape of a capital 'I'. The core of the I-beam, better known as the web, will ensure that resistance against shear forces is provided. Except for the web, the I-beam also consist of flanges, taper or parallel flange, on either side of the web and at both ends. The flanges provide resistance to bending moments.
In the construction industry I-beams are used as cross sections providing strength to girders, it also provides support to joists which in turn support ceilings and/or floors. They are also widely used in the construction industry as a support for buildings to ensure that the structure is strong enough. Even though I-beams can resist bending, it should preferably not be used in cases where torque forces are present along the axis or length of the beam as they are not torsion resistant.
I-beams can also be used as tracks for trolley wheels and lift supporting frames as well as trailer and truck bedding frames.
The size of I-beams are determined by the weight it should be able to support and will differ from application to application and structure to structure.
Please see below the dimensions and properties for the taper flange I-beam.
Dimensions and properties for parallel flange I-beams: I-sections (Parallel flange)(Universal Beams)