What’s the Difference Between Hot & Cold Rolled Steel?

Hot Rolled Steel

Hot rolled steel is a type of steel that has been manufactured using a specific process. This process involves heating the steel to the incredibly high temperature of 926° Celsius (or 1700° Fahrenheit) and then roll-pressing it into the desired shape before it’s set aside to cool down.

Pros and Cons of Hot Rolled Steel

Advantages

• Hot rolled structural steel is much easier to make, shape and form than the cold rolled alternative due to the benefits of heating steel. Therefore, this advantage makes it a cheaper option on average than cold rolled steel due to the time saved in manufacturing. 
• Numerous processes can be applied to hot rolled steel to create an attractive surface finish, including removing surface scaling by grinding, sandblasting, and acid-bath pickling, all of which create a better surface to apply paint or other surface coatings if necessary.

Disadvantages

• Hot rolled steel should only be used when exact shapes and sizes aren’t required, as the cooling process results in an uncertain shrinking that reduces the amount of control involved in the steel fabrication process. This makes it much more difficult for steel fabricators to match your specifications about the steel’s final size and shape. If this is more important to you than the steel’s price, you should consider using cold rolled steel instead.

Cold Rolled Steel

Compared to hot rolled steel, the process of cold rolling is longer but comes with added advantages. Similarly to hot rolled steel, this steel fabrication process also involves heating, roll-pressing, and cooling steel. However, cold rolled steel is then roll-pressed again at room temperature before being processed further at cold reduction mills to achieve the desired shape and size according to the customer’s request.

Pros and Cons of Cold Rolled Steel

Advantages

• Due to the exacting processes involved in creating cold rolled steel, the result is a much more consistent and accurate shape than hot rolled steel. Structural steel fabricators can roll the steel to have straight edges, with well-defined edges and corners, meaning that much more bespoke designs can be created.
• Asking a steel fabricator to use cold-rolling processes allows them to use a broader range of surface finishes, resulting in a smoother and shinier surface on the steel.
• Cold rolled steel tends to be stronger than hot rolled steel, providing stronger resistance to repeating use and other issues that can reduce the durability of weaker materials.

Disadvantages

• Choosing to cold roll your steel comes with more expense, as the intensity of the process means it takes longer on average than hot rolling steel.
• Cold rolled structural steel undergoes a higher level of pressure due to the added processes involved. Therefore unpredictable warping can occur if the steel fabricators do not relieve the pressure on the steel before cutting, grinding or welding.

Explaining the Differences Between the Two Options

If you struggle to understand the differences between hot rolling and cold rolling steel, the main difference is how the two types of steel are created. Deciding whether to use heat during the steel fabrication process results in the type of rolled steel you end up with. This choice doesn’t affect the steel grade or specifications, as any type of steel can be either cold or hot rolled, depending on the project’s needs.

Another way of being able to tell between hot and cold rolled steel is the appearance of the final product. Hot rolled steel tends to have a scaly surface with rounded edges, whereas cold rolled steel has an oily or greasy finish with sharp edges. Each project is unique, so you need to decide your main priorities and choose a rolling process to match those.

Steel Fabrication Services Nearby

Hopefully, you now feel more confident in understanding whether hot or cold rolled steel is better for your project. If you’re looking to buy steel online, Buy A Beam is an easy-to-use tool that eases that process, helping you gather the materials necessary to complete your projects. We can connect you with local structural steel fabricators who will supply you with quality materials according to your requests. If you have any further questions, feel free to contact us today.