Here at Metro Steel our customers often ask us the difference between cold and hot rolled steel, so with this in mind, we thought that it would be a good idea to explain the two processes in further detail.
Hot rolled steel
Hot rolled steel is a process that involves rolling the steel at an exceptionally high temperature (typically in excess of 920° Celsius). The reason that it’s taken to such a high degree of heat is because at this temperature, it falls above the re-crystallisation temperature. When this happens it’s far easier for it to be shaped and formed. Not only this, it can also be made in much larger pieces. Finally, because it can often be manufactured quickly, it’s considered cheaper to buy than cold rolled steel. The only real downside to steel that’s been hot rolled is the fact that when it cools it naturally shrinks giving less control of the size and shape of the end product. Therefore it’s best used in situations where precise shapes and tolerances aren’t required. As a result hot rolled steel, bars are often used in the welding and/or construction industry. As such they’re ideal for railway tracking and I-beams
Cold rolled steel
Essentially cold rolled steel is treated in exactly the same way as hot rolled steel except that it has to endure one final process. Cold reduction mills reduce the heat of the steel gradually letting it cool at room temperature. Once cooled it’s tempered and rolled again. The main advantages of cold rolling steel is that it can be produced to more accurate demands and tolerances because it won’t shrink. It can also be produced in a wider range of surface finishes and as a result can easily be polished, turned, or ground to specification. More often than not, cold rolled products provide a superior surface finish, tolerance, and straightness that those of the hot rolled variety and as a result should be used in situations where surface condition, tolerance, straightness and concentricity are key.
If you want to find out more about hot or cold rolled steel and how it’s produced or can’t decide what’s best for your project then speak to the experts at Metro Steel. We’ve been fabricating and processing stainless steel to meet a wide range of requirements for many years and as such have become a ‘go to’ company for quality steel products over the years. Contact us on 07 3204 1000 today and talk to our friendly and experienced team. We’re only to happy to help!