There are many out there who wonder what the inherent differences are between hot rolled steel and cold rolled steel. While both are very common, there are subtle differences that should definitely be accounted for when choosing metal products for specific applications. There are advantages to both and we will outline some of those for you in this blog entry.
Hot rolled steel is milling process in which steel is rolled at temperatures that soar north of 1700 degrees. These temperatures are above the threshold for the recrystalization for steel which means it will be malleable and shapeable. Utilizing such high temperatures allows for projects of much larger sizes to be completed. Hot rolled steel is also more affordable than cold rolled steel as the process is rarely delayed which means the steel will not need to be reheated in order to finish a project (which is common with cold rolled steel). I-beams and railroad tracks are two common examples of items that are fabricated using the hot rolling method. Most applications that utilize hot rolled steel do not have strict size, shape or tolerance mandates.
Cold rolled steel is basically a more extensive version of the hot rolling method. Following the heating up and shaping of the steel, a cooling process (at room temperature) is started before being followed by tempering or annealing/ rolling. This process makes it so that projects can be more accurately shaped along with several other advantages such as:
- Turning, which will get rid of imperfections along the surface
- Cold drawing increases the overall strength and eliminates further thermal treatments
- Grinding allows for more varied size possibilities, which means more dynamic projects are also possible
- Polishing will smooth out the surface and give the product more overall visual appeal.