When it comes to steelmaking, production can be divided into two basic groups: cold rolled and hot rolled steel. In earlier eras, molten steel was cast into blocks known as ingots. These ingots were convenient to stack and ship, and could be melted back down when needed for use. In current times, steel manufacturing is done on a massive and continuous scale. To make this process more efficient, manufactured steel is produced to be as close to a finished product as possible.
Newly forged steel emerges as a continuous slab of red-hot metal, which is then fed into a series of mills. The process is similar to a home pasta maker: with each consecutive rolling, you will end up with a thinner and thinner result. As the steel progresses through the mills, the metal remains hot enough to stretch and thin out into a long strip. Once rolled out to the desired thickness, it can be cut into shapes such as bars, or thinned enough to be rolled into coil.
Most Popular Grades
Hot rolled steel is available in several different grades, which are the standards set for a steel type. Generally, steels in North America conform to the standards set by the American Society for Testing and Materials (ASTM), or those set by the Society of Automotive Engineers (SAE). ASTM steel grades always begin with an “A”, which is the letter assigned to ferrous metals. SAE steel grades use a four-digit number for identification.
A36 Hot Rolled Steel
One of the most popular grades of hot rolled steel, A36 is a low carbon steel alloy. The low percentage of carbon within A36 steel means it is highly versatile: it can easily be formed, machined, or welded.
The low amounts of other alloying elements such as nickel and chromium make A36 steel just average in corrosion resistance, but also keeps the price relatively low. For this reason, it is widely used in applications where cosmetic appearance is not a priority. You will often find A36 hot rolled steel used for heavy duty construction and equipment manufacturing.
Common applications include:
• Bridge and building construction
• Automotive frames and trailers
• Agriculture equipment
• Oil and gas equipment
1018 Hot Rolled Steel Bar
Another popular choice of hot rolled steel is 1018, which is a similar grade to A36. A36 is often the top choice in manufacturing, but 1018 will be selected if the application calls for bar or strip steel. It is even lower in carbon percentage than A36, and this low carbon in 1018 allows for excellent formability. The low carbon level also allows 1018 to be a fairly ductile type of steel which can be easily bent and machined.
Common applications include:
• Gears
• Pins and studs
• Steel bar in square, rounded square, hexagonal and other shapes
1011 Hot Rolled Sheet and Plate
SAE 1011 is a strong, low-alloy form of hot rolled steel. Its low percentages of carbon and other alloying elements means this steel grade is very hard and strong, while remaining easy to drill, form and weld. 1011 is strong and durable, but can be vulnerable to corrosion with its low alloying percentages. Exposed to the elements, the iron content of 1011 will begin to discolor, corrode, and roughen its surface. For added corrosion protection, an outer layer is often applied to the steel’s surface, through painting or processing such as galvanization.
Common applications include:
• Building and roofing construction
• Shipping containers
• Automotive parts
• Heavy equipment