During hot working of metals the Porosity of the metal is largely eliminated and Grain structure of the metal is refined and Mechanical properties are improved due to refinement of grains.

Structural shapes that can be made with this metal forming process include I-beams, H-beams, T-beams, U-beams, angle iron, channels, bar stock, and railroad rails.
The most commonly rolled material is structural steel.
it is made by Hot rolling.

Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed through a die of the desired cross-section. Rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform.

A two high rolling mill consists of two rolls which rotate At the same speed but in opposite direction.