See all Blog Posts Difference Between Hot Rolled Steel and Cold Rolled Steel Category: Metal Man Knows, Steel, Video Posted: September 11, 2014 Customers often ask us about the differences between hot rolled steel and cold rolled steel. There are some fundamental differences between these two types of metal. The differences between hot rolled steel and cold rolled steel relates to the way these metals are processed at the mill, and not the product specification or grade. Hot rolled steel involves rolling the steel at high temperatures, where cold rolled steel is processed further in cold reduction mills where the material is cooled followed by annealing and/or tempers rolling. Hot Rolled Steel Hot rolling is a mill process which involves rolling the steel at a high temperature (typically at a temperature over 1700° F), which is above the steel’s recrystallization temperature. When steel is above the recrystallization temperature, it can be shaped and formed easily, and the steel can be made in much larger sizes. Hot rolled steel is typically cheaper than cold rolled steel due to the fact that it is often manufactured without any delays in the process, and therefore the reheating of the steel is not required (as it is with cold rolled). When the steel cools off it will shrink slightly thus giving less control on the size and shape of the finished product when compared to cold rolled. Uses: Hot rolled products like hot rolled steel bars are used in the welding and construction trades to make railroad tracks and I-beams, for example. Hot rolled steel is used in situations where precise shapes and tolerances are not required. Cold Rolled Steel Cold rolled steel is essentially hot rolled steel that has had further processing. The steel is processed further in cold reduction mills, where the material is cooled (at room temperature) followed by annealing and/or tempers rolling. This process will produce steel with closer dimensional tolerances and a wider range of surface finishes. The term Cold Rolled is mistakenly used on all products, when actually the product name refers to the rolling of flat rolled sheet and coil products. When referring to bar products, the term used is “cold finishing”, which usually consists of cold drawing and/or turning, grinding and polishing. This process results in higher yield points and has four main advantages: Cold 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. All cold products provide a superior surface finish, and are superior in tolerance, concentricity, and straightness when compared to hot rolled. Cold finished bars are typically harder to work with than hot rolled due to the increased carbon content. However, this cannot be said about cold rolled sheet and hot rolled sheet. With these two products, the cold rolled product has low carbon content and it is typically annealed, making it softer than hot rolled sheet. Uses: Any project where tolerances, surface condition, concentricity, and straightness are the major factors. Don’t have time to read the blog? You can check out our video below to find out the difference between hot rolled steel and cold rolled steel: Metal Supermarkets Metal Supermarkets is the world’s largest small-quantity metal supplier with over 100 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985. At Metal Supermarkets, we supply a wide range of metals for a variety of applications. Our stock includes: mild steel, stainless steel, aluminum, tool steel, alloy steel, brass, bronze and copper. We stock a wide range of shapes including: bars, tubes, sheets, plates and more. And we can cut metal to your exact specifications. Visit one of our 100+ locations across North America today. Share: Facebook Twitter LinkedIn E-Mail Tags: cold rolled steel, hot rolled steel Related blog articles What is the Spark Test? What is Oxygen Free Copper? What is Abrasion Resistant Steel?