Cold calibration of steel bars

As rolled products do not always offer sufficient dimensional accuracy or the right appearance for their intended use, cold sizing is designed to provide bars with the following properties in common:

• a white, scale-free appearance, hence the names "bright steel products" in English and "blankstahl" in German;

• reduced dimensional tolerances ;

• straightness suitable for use on automatic machines or for assembly into precise mechanical units.

Two principles dominate:

• Drawing, which involves cold forming to obtain profiles of any shape;

• peeling, which applies only to round parts, and consists in removing metal by machining (turning).

The tolerances of stretched or peeled rounds can in turn be tightened by grinding. In this process, the periphery is abraded using grinding wheels.

Grinding can also be carried out directly on small-section rolled rounds, instead of peeling. The term used in this case is grinding.

The 500,000 tonnes consumed annually on the French market, half of which is produced in France, find countless applications in many sectors of the mechanical engineering industry, and in particular in bar turning.

One third of cold rolled production is for free-cutting steels, whose main characteristic, in terms of chemical composition, is a high sulfur and often lead content, both of which enhance machinability.

Other sectors of activity include the following application examples:

• in the automotive industry (the main user, either directly or through its subcontractors):

• steering assembly components: steering wheel axle, rack and pinion, connecting rods,

• suspension components: torsion bars, anti-roll bars, springs, shock absorber rods,

• seat equipment, seatbelt fasteners ;

  • in household appliances: rotor shafts ;

  • in agricultural and public works machinery: cylinder rods, transmission shafts ;

  • in the field of tools: screwdrivers, drill bits ;

  • locksmithing: hinges, bolts ;...