1. Basic products used

Cold rolled sections are made from a number of materials, each with its own characteristics. There are two main families:

• hot-rolled laminates, available in formats ranging from 1.5 mm × 600 mm to 12 mm × 2,000 mm. Their thickness and width tolerances are relatively wide;

• cold-rolled; these correspond to formats ranging from 0.3 mm × 600 mm to 2 mm × 1,850 mm. Their thickness and width tolerances are tighter than those of hot-rolled products.

For narrower formats, operations such as diverting or slitting are used, which have the effect of tightening width tolerances, while slitting wide strips into multiple coils is less costly due to lower fall-offs.

Hot-rolled products have the disadvantage of a highly abrasive scale layer. They can undergo an...