Cold rolling is a process by which the sheet metal or strip stock is introduced between rollers and then compressed and squeezed. The amount of strain introduced determines the hardness and other material properties of the finished product.
The advantages of cold rolling are good dimensional accuracy and surface finish.
Cold rolled sheet can be produced in various conditions such as skin-rolled, quarter hard, half hard, full hard depending on how much cold work has been performed. This cold working (hardness) is often called temper, although this has nothing to do with heat treatment temper.
In skin rolling, the metal is reduced by 0.5 to 1% and results in a surface that is smooth and the yield point phenomenon–excessive stretching and wrinkling in subsequent operations, is eliminated. This makes the metal more ductile for further forming and stretching operations.
Quarter Hard, Half Hard, Full Hard stock have higher amounts of reduction, up to 50%. This increases the yield point; grain orientation and material properties assume different properties along the grain orientation. However, while the yield point increases, ductility decreases.
Quarter Hard material can be bent (perpendicular to the direction of rolling) on itself without fracturing. Half hard material can be bent 90 ; full hard can be bent 45 . Thus, these materials can be used for in applications involving great amounts of bending and deformation, without fracturing.
Sinotech offers an exceptionally wide range of secondary processes that are applied to metals formed in hot or cold processes. Sinotech’ Supplier Quality Engineers determine the availability of the process within the metal forming facility, as well as the quality. If the internal secondary processes do not meet Sinotech standards then the processes are carried out in Sinotech-audited and qualified off-site secondary processing facilities. Sinotech has audited, qualified and worked with QS-9000 and ISO certified secondary processing facilities in China, Taiwan and Korea for over 12 years. Sinotech is dedicated to managing your project on-site and delivering parts to you at lower prices but the same quality, service and terms as a domestic supplier.