Steel comes in many shapes, sizes and finishes depending on the desired outcome of the product you are fabricating. Understanding the differences between steels is important as hot rolled and cold rolled come with their own benefits and drawbacks.
Each type of steel can be used for many applications, however they all have unique properties. Prefabricated raw steel material commonly comes as either hot rolled steel or cold rolled.
Hot rolled steel:
Hot rolled steel is steel that has been roll-pressed at very high temperatures. The steel is then left to cool and slightly shrinks during the process. The final shape of the material after cooling is unpredictable, making it less suitable for an aesthetically focused design.
The benefit of hot rolled steel is that it requires less processing making the material cheaper to purchase. On the other hand, the steel comes with a textured surface, slightly rounded edges and unique shapes.
Cold rolled steel:
Cold rolled steel follows the same beginnings as hot rolled steel, however, is further processed to achieve more specific finishes. Cold rolled steel is often used for more technically precise applications, or where aesthetics are important.
Cold rolled processes include:
- Drawing – increases the yield and tensile strengths, often eliminating further costly thermal treatments
- Turning – gets rid of surface imperfections
- Grinding – narrows the original size tolerance range
- Polishing – improves surface finish.
These processes will produce steel with closer dimensional tolerances making it a stronger, more durable material than hot rolled.
Cold rolled steel delivers with an oily finish, a very smooth surface and very sharp edges.