Hot Rolled vs Cold Rolled Steel: What’s the Difference?
If you work with metals, you’ve probably seen metal suppliers advertising hot rolled steel and cold rolled steel. These types of steels are manufactured using different temperatures to bring different qualities to the finished product. The Short Iron Store in Fort Worth carries both varieties, and we’re happy to recommend the material that best suits your needs. Let’s learn more about the differences between hot and cold rolled steel.
Hot rolled steel is typically the less expensive of the two because its manufacturing requires less time and labor. It tends to be used on high-volume projects like railroad tracks and farm equipment. Cold rolled steel has a smoother, more uniform appearance, so it is a popular choice for car bodies and other projects where looks are a factor.
The Production Process
The hot rolling process begins by heating steel past its recrystallization point. This requires an extremely high heat — approximately 1700° F. At this temperature, the steel becomes soft and easy to form and shape. It is rolled while it’s still soft, and more steel is added onto it to produce a larger quantity of metal.
The steel is then cooled at room temperature. It slowly shrinks as it cools. This method makes the finished steel less prone to cracking when it is worked or quenched later. Because hot rolled steel is minimally processed, it requires less time and labor to create. This is why it’s typically less expensive than cold rolled steel.
Cold rolled steel is similar to hot rolled steel, but there are a few more steps involved in its manufacturing. It is rolled, pressed, stamped, and bent at room temperature, which maintains the strength and integrity of the steel.
Next, the metal is processed further in cold reduction mills and allowed to cool after annealing and rolling. The finished product is shaped into flat sheets, coil products, and bars. This extra processing produces a stronger, smoother product, but also adds to the price of the finished steel.
Properties of Hot and Cold Rolled Steel
After shrinking and cooling, hot rolled steel has a scaly surface that can be ground down or sanded later. Cold rolled steel bars have been turned, ground, and polished, resulting in a smooth product with no surface imperfections.
Finished hot rolled steel isn’t as precisely shaped as cold rolled steel, but it can be made in larger quantities because more steel can be added during its manufacturing. It can be thinned out enough to produce a large volume of sheet metal.
Cold rolled steel is formed into bars, coils, and sheets before sale . It has a superior surface finish, tolerance, concentricity, and straightness when compared to hot rolled.
Uses for Hot and Cold Rolled Steel
Hot rolled steel is used when steel is needed in large quantities, like railroad tracks, I-beams, farm equipment, and car frames. It is often used in welding and construction projects where size and flexibility are more important than intricate shaping.
The construction industry uses cold rolled steel for a number of structural items, like beams, joists, studs, and floor decking. It has also been used to build bridges, storage racks, grain bins, car bodies, railway cars, transmission towers, drainage facilities, firearms, and equipment of all kinds.
All steel is considered to be a green resource because it is renewable, recyclable, and promotes energy efficiency wherever it is installed.
The Short Iron Store Carries Hot and Cold Rolled Steel
We have cold rolled steel available, along with many other steels, aluminums, and specialty metals. Not sure which one you need? Our team is always available to help you choose the right material for your project. Call us today or come by our Fort Worth location to browse our inventory in person!