This looser tolerance makes it easier to force the metal into a variety of different shapes.
Cold rolled sheet metal vs hot rolled.
Cold rolling is done when the metal is able to form new grains as the old ones are deformed by rolling and bending the metal.
But cold rolled steel undergoes additional processing steps resulting in improved properties that can be exploited for different applications.
Cold rolled has a smooth and shiny finish while hot rolled has a grey and scaly finish.
Hot rolled steel involves rolling the steel at high temperatures where cold rolled steel is processed further in cold reduction mills where the material is cooled followed by annealing and or tempers rolling.
During cold rolling the steel is annealed or exposed to heat and allowed to cool which improves ductility.
Hot rolled steel is rolled or shaped at a high temperature while cold rolled steel is rolled at room temperature.
As an example a hot rolled steel product may have a yield strength of 235 mpa.
In comparison a cold rolled steel product with the same chemical composition has a yield strength of 365 mpa.
Once hot rolled steel has cooled it is then re rolled at room temperature to achieve more exact dimensions and better surface qualities.
Finished products created by the cold rolled steel process include bars strips rods and sheets which are usually smaller than the same products available through hot rolled methods.
Each type of steel has its advantages and disadvantages and costs for the two types of steel are also different.
There are some fundamental differences between these two types of metal.
Cold worked steels are typically harder and stronger than standard hot rolled steels.
Both hot rolled steel and cold rolled steel start out in essentially the same way and both can have the same grades and specifications.
During the hot rolling process steel is heated to its melting point while being worked changing the composition of the steel to make it more malleable.
The main advantages of cold working are.
Cold rolled has sharper corners and more precise dimensions than hot rolled.
Whereas cold rolled steel is processed in cold reduction mills followed by annealing and tempering.
Hot rolling and cold rolling are two methods of shaping steel.
Typically mills take hot rolled steel after it s mostly or completely cooled and work it to its final dimension by either rolling it extruding it or drawing the metal over a mandrel.
Cold rolled steel is essentially hot rolled steel that has been through further processing.
Basic difference between hot rolled and cold rolled steel is the way they are processed.
The differences between hot rolled steel and cold rolled steel relates to the way these metals are processed at the mill and not the product specification or grade.
The smaller products are also much more tolerant than the larger hot rolled versions.
Thus the yield strength of cold rolled steel is higher than that of hot rolled steel.
When the hot rolled metal cools it will reconfigure making the finished product with a looser tolerance when compared to the cold rolled metal.
