This International Standard applies to cold-reduced carbon steel strip with a mass fraction of carbon over 0,25 % made from the steels specified in Table 1. It is commonly produced in thicknesses of 6 mm and under, and in widths up to 600 mm exclusive, in coils and cut lengths. The strip is ordered in the as-delivered condition, as specified in 6.1 or Clause 5, and is predominantly used for springs, but also for other highly stressed parts of many different types. Steel designations CS55 to CS95 may be supplied in the quenched and tempered condition.

This International Standard does not apply to alloy steels or stainless steels.

Cold-reduced carbon steel strip is furnished in the following types:

a) full hard, where a very stiff, springy product is produced to obtain full hardness after the final rolling (it is intended for flat work not requiring the ability to withstand cold forming);

b) annealed, which is intended for applications requiring moderate cold forming;

c) quenched and tempered, which is intended generally for the production of steel springs where the appropriate combination of strength, hardness, toughness and ductility can be achieved;

d) intermediate hardness, which is intended for applications where cold forming is slight or where a moderately stiff, springy product is needed.

Cold-reduced carbon steel strip is characterized by close dimensional tolerances and good surface finish and, in the cold-rolled and quenched and tempered condition, it is possible to attain high values for hardness and tensile strength.