When to Use cold rolled round bar？

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 relate to how these metals are processed at the mill, not the product specification or grade. Hot rolled steel involves rolling the steel at high temperatures, whereas cold rolled steel is processed further in cold reduction mills where the material is cooled, followed by annealing and/or tempers rolling.

You can find more information on our web, so please take a look.

Hot Rolled Steel

Hot rolling is a mill process that involves rolling the steel at a high temperature (typically at a temperature over ° F), which is above the steel&#;s recrystallization temperature. This process begins with heating large steel slabs, billets, or blooms and then rolling them at high temperatures. The rolling process involves passing the heated steel through a series of rollers to achieve the desired shape and thickness. 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 typically has a rougher, more scaled surface than cold rolled steel. The scaling, formed as the steel cools at room temperature, is often removed later via a process called pickling, which involves the use of acid baths. However, the slightly irregular surface finish and less precise dimensional tolerances of hot rolled steel make it less suitable for applications requiring a smooth, refined surface or tight dimensional tolerances.

Hot rolled steel is typically cheaper than cold rolled steel because 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 shrinks slightly, thus giving less control over 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 the product name actually 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 compared to hot rolled.

Cold finished bars are typically more challenging 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.

The advantages of cold rolled steel include its superior surface finish, higher strength, and tighter dimensional tolerances compared to hot rolled steel. However, the increased strength and reduced ductility of cold rolled steel can make it more challenging to work with in certain fabrication processes than hot rolled steel.

Uses: Any project where tolerances, surface condition, concentricity, and straightness are the major factors. Due to its improved surface finish and tighter tolerances, cold rolled steel is suitable for applications where aesthetics and precise dimensions are important. It is commonly used in applications requiring high precision and a high-quality finish, such as in manufacturing appliances, automotive parts, furniture, and metal containers. It is also frequently employed in the construction of consumer electronics and in metalworking projects where a smooth, polished appearance is desired.

Choosing Between Hot Rolled vs. Cold Rolled Steel

Understanding HR and CR sheet differences helps ensure that you choose the most appropriate material for your project&#;s requirements. Here are some key points to consider when deciding between hot rolled and cold rolled steel:

Application Requirements &#; If the project requires high precision, tight tolerances, or a smooth surface finish, cold rolled steel is typically the better choice. Hot rolled steel is often sufficient for projects where its structural integrity is more important than its appearance. Its ease of fabrication also makes it suitable for welding and bending processes.

Cost Considerations &#; Hot rolled steel is generally less expensive than cold rolled steel because of its simpler production process and lower finishing requirements. If cost is a primary concern and the application permits, opting for hot rolled steel can be more economical. Cold rolled steel, while more expensive, offers higher strength and a better surface finish and may be worth the investment for some projects.

Desired Material Properties &#; Cold rolled steel typically offers higher strength and hardness due to the cold working process. Hot rolled steel has better ductility, which is beneficial in applications that involve forming or shaping the steel.

Aesthetic Preferences &#; If the appearance of the steel is important, cold rolled steel&#;s smooth, polished surface may be preferable. It&#;s ideal for projects where the steel will be visible and aesthetics are a consideration. In applications where the steel will be coated, painted, or hidden, the rougher surface of hot rolled steel may not be an issue.

Lead Time &#; Availability of the specific type and grade of steel required for your project can also influence the decision. Some steel grades are more readily available in either hot rolled or cold rolled form.

Don&#;t have time to read The Difference Between Hot-Rolled and Cold-Rolled Steel blog?

You can check out our video below to find out the difference between hot rolled steel and cold rolled steel:

Know Your Grades of Steel and Uses

To know the difference between cold-rolled vs. hot-rolled steel bars, it is necessary to understand that steel has grades according to its component alloys. For example, there are carbon, nickel, chromium, chromium-vanadium, nickel-chromium, tungsten, molybdenum, silicon-manganese, and Nickel-chromium-molybdenum steel alloys in various types of steel.

Each steel type has specific properties that react to cold and heat. For example, stainless steel is a chromium-carbon alloy that allows for temperatures of deg. F. for 304 and 316 stainless designations and up to deg. F. for high temp stainless grade 309(S). The temperature range for 310(S) is up to deg. F.

Hot Rolled Steel Bar Grades:

• ASTM A36 useful for general structural applications
• HR Bars is a medium grade of carbon steel best to use when greater hardness and strength are a must.
• HR Bars 11L17 useful for machining
• HR Bars is useful for its hardness and strength for axles, bolts, machine parts, studs, shafts, and gears when flame and induction-type hardening is a must.
• HR Bars has a uniform heat treatment response for machinability

Cold Rolled Steel Bar Grades:

• CR Bars 12L14 &#; useful in high-end fast machining speeds such as screw machining. It has fine surface quality and flexibility.
• CR Bars &#; Because of its low carbon and medium manganese content, this grade offers only fair use for machinability but can undergo welding and brazing. 

What is the Difference Between Cold Rolled vs. Hot Rolled Steel Bars?

In metal manufacturing, the difference between cold-rolled and hot-rolled steel is the process to create and form both. As their names indicate, ambient temperatures are helpful for cold-rolled steel and heat for hot-rolled steel.

Goto Xingtai Steel to know more.

The other difference between the two lies in cost. Hot-rolled steel is less expensive since it goes manufacturing quickly and without reheating. The construction and welding industries favor hot-rolled steel. Hot-rolled steel grades are not as significant as the manufacturing process.

Cold-rolled steel tends to shrink after it is created and formed, adding to the metal manufacturing time.

Hot Rolled Steel Bars

Hot-rolled steel bars are useful for I-beams, general fabrication projects, structural supports, walkways, ramps, and trailers.

A steel round bar is often seen in machined parts like axles, frameworks, supports, bolts, etc. A steel round bar is available in hot or cold-rolled steel.

In metal manufacturing, a round steel bar is measured in diameter. Cold-rolled round bars are cylindrical and commonly useful for rods, spindles, sprockets, and shafts.

Hot rolled round bars are formable, challenging, and preferred for welded steel materials. It is easily shaped and easy to drill.

How Metal Fabricators Choose Cold Rolled vs. Hot Rolled Steel

Whenever metal fabricators take on projects that require cold-rolled or hot-rolled steel, they must first decide on the need for precise dimensions and the quality of the steel surface.

When choosing a metal fabricator for a project, they should work closely with metal manufacturers in various industries and offer precision services for the hot-rolled or cold-rolled steel required. These services should include the following:

Metal fabricators use hot and cold rolled steel that requires precision grinding of a precision-ground bar to produce according to customer specifications. Working with hot and cold rolled steel to shape, form, bevel, and grind for various uses has become an industrial art form.

For example, the ratio of metal fabricators in the U.S. is under 25,000. This keeps a metal fabricator like Advance Grinding Services Inc. continuously busy when customers request the number of metal grinding projects has grown by overwhelming numbers.

Advance Grinding is an Industry Leader

A critical feature of the skilled staff of Advance Grinding Services Inc. is that they are certified by ISO : standards. This symbolizes the excellent quality set by the Advanced Grinding Services team. In addition, Advanced Grinding Services takes pride in maintaining SOTA (state-of-the-art) technology.

This ensures customer satisfaction which is an Advanced Grinding Services priority. In addition to exceptional performance, the staff maintains timely service customers rely on to expedite their projects and needs.

Advance Grinding Services Inc. is ready to assist if your project requires a hot or cold rolled precision ground bar, centerless grinding, or other additional services. For more details or to request up to three quotes online, visit Advance today!

For more cold rolled round barinformation, please contact us. We will provide professional answers.