2. Geometric features

The rolling stage involves a wide variety of geometric shapes to be achieved, together with significant variations in dimensions during the various stages imposed on the product.

Blooms, billets and bars for forging, closed-die forging, stamping and drawing, and wires for drawing in some applications, make up a range of rolled products whose final dimensions and shape change little over time.

On the other hand, the dimensions and shapes of other rolled products are constantly evolving. The external dimensions of beams are increasing (high-rise buildings), and the thicknesses of the web and flanges are either becoming thinner (light structural work) or thicker (building columns), depending on their use.

• The metric mass of rails has risen sharply in just a few decades (as in the case of high-speed...