To understand the difference between hot and cold rolled steel, one must first understand the fundamental difference between hot rolled vs cold rolled steel. What distinguishes these two types of steel is the process by which each is made. These differences originate at the mills where the steel is produced and often refer to the heat treatment associated with production.
With competitive price and timely delivery, Xingtai Steel sincerely hope to be your supplier and partner.
Hot rolling, as its name entails, refers to a process in which the steel is heated to temperatures above or around ⁰ F. This causes the steel to surpass the recrystallization temperature. The steel can be more easily shaped and formed in this state. Hot rolled steel is generally cheaper than cold rolled steel due to the level of difficulty and duration of the production process. Since the hot rolled steel is only heated once during this process, the manufacturers have less control over the size and shape of the finished products when compared to products that have been cold rolled or finished.
Manufacturing Process: The steel is heated, rolled, and then cooled, which can lead to slight variations in shape and size due to shrinkage.
Surface Finish: It has a rough, scaly surface due to oxidation from high temperatures.
Strength & Durability: Less precise in dimension but strong, making it ideal for structural applications.
Cost: Generally cheaper than cold rolled steel because it requires fewer processing steps.
Applications: Used in construction, bridges, railroad tracks, I-beams, sheet metal, and automotive frames.
Due to the differences in the production processes, hot rolled steel is often cheaper than cold finished steel. As stated above, manufacturers have less control over the quality and specifications of hot rolled vs cold rolled steel. Therefore, hot rolled steel bars are used when precise shapes and tolerances are not required. Some applications of hot rolled steel bars could include making I-beams, general fabrication projects, structural supports, walkways, ramps, and trailers.
Cold rolled steel has similarities in the start of its production process that align with the hot rolled steel production process. The most significant difference is that cold rolled steel is essentially hot rolled steel that has been further processed. Cold reduction mills cool the material to ambient temperatures, followed by annealing and/or tempers rolling. Controlling temperatures throughout the cold rolling process will allow for steel production with precise dimensional tolerances and a wide range of surface finishes.
Manufacturing Process: Hot rolled steel is further processed by rolling it at room temperature, which increases its strength through work hardening.
Surface Finish: It has a smooth, polished, and often oily surface, making it ideal for applications requiring a clean appearance.
Contact us to discuss your requirements of cold rolled round bar. Our experienced sales team can help you identify the options that best suit your needs.
Strength & Durability: Stronger and harder than hot rolled steel due to strain hardening during the rolling process.
Dimensional Accuracy: More precise and uniform in thickness, width, and length.
Cost: More expensive than hot rolled steel because of additional processing.
Applications: Used in automotive parts, appliances, furniture, metal containers, and precision components where a smooth finish and high strength are important.
Cold finished bars and their production process result in higher yield points and have four main advantages. Cold drawing increases yield and tensile strength, eliminating further expensive thermal treatments; turning removes surface imperfections; grinding narrows the original size tolerance range; and polishing improves surface finishes. These qualities make cold products superior in surface finish, tolerance, concentricity, and straightness when compared to hot rolled. The length of production and quality of finished products make cold finished bars being more expensive than hot rolled bars. Real-world applications of cold rolled steel bars may include the production of gears and shafts, oil and water well shafting, industrial buildings, and products that demand defect-free surface finishes.
You may have heard of both hot rolled steel and cold rolled steel, but do you know the difference between them? If not, we’re here to help.
Production of both hot rolled steel and cold rolled steel starts with the same steps. They're both initially processed at extremely high temperatures. However, once the treated steel is ready, cold rolled steel goes through a few extra steps. The mill lets the metal cool off until it's room temperature, then draws it through rollers or puts it through annealing treatment. This additional labor makes it more expensive than hot rolled steel.
There are three main visual differences between hot rolled steel and cold rolled steel. Hot rolled steel has rounded edges, a rough surface texture, and no grease on its finish. Alternatively, cold rolled steel has sharp edges, a very smooth surface texture, and an oily or greasy feel to it.
The pros and cons of hot rolled steel come down to strength versus price. Hot rolled steel is weaker than cold rolled, but it’s also cheaper since it doesn’t go through the second production process. However, this doesn't automatically mean cold is better just because it's stronger and more expensive.
The more significant difference in how to use it is how specific your material needs are. Hot rolled steel is perfect for welding, railroad tracks, and I-beams because there is less concern for smooth finishes and precise shapes. The tolerance range is also wider because the metal shrinks during the cooling process, so you can't be as exact with the measurements.
While hot rolled steel has a rougher surface, the aesthetic difference is fixable if that's your only reason for avoiding it. It will add to the total cost, but you can grind or sandblast the steel to a smooth finish.
Cold rolled steel is going to cost more, but it may be worth the higher price tag if it fits your needs. You're going to pay for tight tolerance, smooth finish, and consistency between pieces.
So when should you splurge on the higher-cost option? In addition to the visual benefits of a smooth surface, cold rolled steel is best when you need consistency and tight tolerances on a project. Workers shape the steel at room temperature, so there's no risk of shrinkage during the cooling process. You'll know the exact dimensions you're getting, and every piece is uniform.
If you are looking for more details, kindly visit a706 rebar.