GRADES OF HOT ROLLED STEEL
When it comes to an excellent combination of mechanical properties such as tensile strength, shear strength, toughness, hardness, and ductility, it is hard to beat carbon steel. When it comes to having all of those mechanical properties at an affordable rate, it is hard to beat hot rolled carbon steel. Hot rolled carbon steel is a metal alloy comprised mostly of iron with some carbon that is rolled down in size from an ingot, at a heat level above its recrystallization temperature. Forming hot rolled carbon steel at this high temperature gives it excellent mechanical properties while keeping costs lower than a cold-rolled carbon steel. There are many grades of hot rolled carbon steel available, which might raise the question: “What is the difference among all of the hot rolled steel grades?” This article answers that question.
The following are some common Grades of Hot Rolled Steel:
A36
C1010
C1018
A1011
C1026
A500
C1045
C1141
A36
ASTM A36 steel is one of the most popular hot rolled steels that Metal Supermarkets sells. When it comes to hot rolled steel, Metal Supermarkets carries product with designations from two organizations: the American Iron and Steel Institute (AISI) and the American Society for Testing and Materials (ASTM). A36 is an ASTM-designated material. It is considered a low carbon steel, since its carbon content is generally between 0.25% and 0.29% by weight. The “36” in A36 is significant in that it specifies the minimum yield tensile strength at 36,000 psi. A36 is very machinable, weldable, and has excellent mechanical properties. This is part of the reason it is so popular, and why it is widely used in structural applications. Metal Supermarkets sells ASTM A36 in round bar, rectangular bar, square bar, channel, angle, plate, tread plate, round tube, and shafting.
C1010 and C1018
AISI C1010 and AISI C1018 are two hot rolled steels that are very similar. They are both low carbon. In fact, the only noticeable difference between their chemical compositions is their carbon content. C1010 is 0.08% to 0.13% carbon by weight and C1018 is 0.14% to 0.20% carbon by weight. The difference in carbon content between them can result in slight variations to ductility and tensile strength, but for the most part they are quite similar. They are both weldable, machinable, and formed relatively easily when compared with alloy and high carbon steels. Metal Supermarkets provides C1010 in round tube and C1018 in round bar and mesh sheet. C1010 and C1018 are widely used in structural applications, and are also used frequently in the automotive and furniture industries.
A1011
A1011 is another ASTM-designated hot rolled steel that Metal Supermarkets offers. This grade can also have small amounts of other trace elements that make it a very versatile steel. It is widely used in sheet steel structural applications, automotive bodies, drums, and general metal fabrication. Metal Supermarkets provides A1011 in the flat sheet form as well as the expanded metal form.
C1026
C1026 is an AISI-designated steel that very closely mimics the ASTM-designated A36 steel mentioned above. Their chemical properties have a lot of overlap, with their carbon contents both being on the upper limit of what constitutes a low carbon steel. AISI 1026 has a target carbon content of 0.22% to 0.26% by weight. When they are both in the hot rolled condition, their mechanical properties are quite similar as well. Both AISI C1026 and ASTM A36 are great choices when a hot rolled steel is needed, with more strength than an A1011, C1010, or C1018 can provide. AISI C1026 is used for structures, automotive components, and furniture, to name a few areas where this hot rolled steel is used. C1026 is available from Metal Supermarkets in square tube and rectangular tube.
A500
ASTM A500 is another low carbon hot rolled steel. It can have up to 0.26% carbon by weight in its chemical composition, and is quite similar to ASTM A36. One main difference between ASTM A500 and ASTM A36 is the shape in which each type of hot rolled steel is available. As previously mentioned, A36 is available in round bar, rectangular bar, square bar, channel, angle, plate, tread plate, round tube, and shafting. A500, on the other hand, is solely used for tubing. Metal Supermarkets carries A500 in square and rectangular tubing in particular. Applications for ASTM A500 are similar to other low carbon hot rolled steels; they are used abundantly in structural applications.
C1045
C1045 is another AISI designated hot rolled steel. What makes this hot rolled steel different from the previously mentioned steels is that it is a medium carbon steel. With 0.42% to 0.50% carbon by weight, it generally provides more strength than low carbon hot rolled steels. C1045 also has enough carbon where it becomes quite receptive to heat treating. This means that through quench hardening and annealing, its mechanical properties can be altered. C1045 is used in applications similar to low carbon hot rolled steel, except it is typically preferred to low carbon steel when strength is more of a concern than ductility. Metal Supermarkets sells AISI C1045 in the form of round bars and plate.
C1141
AISI C1141 is another medium carbon hot rolled steel, similar to C1045. However, AISI C1141 has additions of sulfur and manganese that give it different properties. First, heat treating can be more effective on C1141 than C1045. Second, C1141 is considered a free machining steel. This means that it is easier on machining tools, which is important as carbon content increases because the corresponding increase in hardness can hinder machinability. It is important to note, however, that the additions of sulfur that make C1141 easily machinable also make it unweldable, in general. AISI C1141 is available in shafting and round bar forms from Metal Supermarkets. AISI C1141 is frequently used in components that require a lot of machining and in certain types of fasteners.
