How Is Rebar Made?

If you’ve ever had a concrete surface poured at your home, such as a driveway or patio, you’ve also had a key component installed – rebar.

First thing to remember, rebar is reinforcing bar. Steel bars are used as rebar because the elongation of steel due to high temperatures (thermal expansion coefficient) nearly equals that of concrete. Therefore, rebar is incorporated to reinforce concrete and impart the tensile strength needed to make sure concrete stays in place. Since concrete naturally expands, the product helps keep the concrete in check, making sure it will last as long as your structure does.

How Is Rebar Made?

From Scrap Steel

First, most rebar produced in North America is produced using an EAF steel making process, or Electric Arc Furnace. Here, scrap steel is collected from various sources at the steel mill and put into a large ladle where the steel is then melted at temperatures up to 1,800° Fahrenheit. In this state, the molten steel will be poured into a casting.

Molten Steel

Then, the molten steel is poured into the tundish to make to feed into the caster and avoid splashing. In fact, this method also gives the molten steel a smoother flow. Following, the molten steel is poured into a series of casters that gives the steel its shape. As a result, the shapes formed are known as billets which will be used later in the process to form the rebar.

Rough Mill Section

Another key point, after the rebar leaves the casters, it then goes into the roughing mill. At the roughing mill, the larger billets will be hot rolled into small shapes by continuously reducing the billet at each stand on the roughing portion of the mill.

Intermediate and Finishing Sections

After the roughing mill section, the billets pass through the intermediate section of the rolling mill. As it goes through the stands, at this section, the billets begin to take shape into the bars. After the intermediate section of the mill, the bar passes through the finishing section which gives its final shape and that “tied knot” look that is ideal for reinforcing applications.

Cut to Size

From here, the bars enter the cutting section; typically, a flying shear saw to specific lengths that are programmed in by the mill operator. Then, the bars exit onto a cooling bed. Did you know, some of these cooling beds can be the size of a football field?! The cooling section of the mill is used so the material is cooled back to room temperature before the product is sheared to the final customer specific length.


Overall, rebar is then bundled using automated bundling systems to the customer’s specifications. Notably, the rebar is stored in specific bays to make it easy on mill shippers to move onto the customer’s desired mode of transportation. In fact, the product is usually transported by a flatbed truck in 45,000 lb. increments. It can also be shipped on railcars to a desired location.

Rebar Sizes

At Contractors Steel, we carry rebar to the ASTM A615-20 Grade 60 specification in the following sizes:

Bar Number Nominal Diameter
#3 0.375”
#4 0.500”
#5 0.625”
#6 0.750”
#7 0.875”
#8 1.000”
#9 1.125”
#10 1.250”


Where to Buy Rebar? Contractors Steel!

As an industry leading service center, Contractors Steel, powered by UPG supplies the rebar you need, when you need it. Ultimately, whether that is one piece or 1,000 truckloads, Contractors Steel DELIVERS!

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