Generally the billet is plastically deformed at a certain temperature environment, through a dedicated mold, the metal to produce a continuous smooth flow of the process to achieve the deformed geometry requirements. Perforation is to wear a circular cross-section billet deformation tube made of wool.

Technology links are: billet heating - high pressure water descaling - Thermal Centering - perforation - blow borax.

Billet heating: the blank optimum temperature plastic, it is the basis for the entire steel rolling.
High-pressure water descaling: remove the heat of the blank outer oxide scale, reducing system wear resistance.
Thermal Centering: improve low plasticity steel plasticity, effectively reduce the axial perforation resistance, reduce head loss.
Blow Borax: remove the inner capillary surface oxide for reduced rolling resistance.