Round hot-rolled steel is a black rolled steel of round cross-section (hot-rolled for short), for the production of which alloyed, structural or carbon alloys are used. This composition determines the high strength, wear resistance and elasticity of the final product. Rods are formed by hot rolling or cold deformation.

Hot-rolled steel is divided into the following carbon groups:

• Low carbon or mild steel contains 0.3% or less carbon by volume.
• Medium-carbon steel contains from 0.3 to 0.6% carbon.
• High-carbon steels contain more than 0.6% carbon.

The standards regulating the diameter of such a roll:

• European: DIN 10060:2004 - diameter from 10 to 250 mm
• American: ASTM 1040 - diameter from 6.35 to 241.3 mm
• International: ISO-1035-4 - diameter from 15 to 200 mm