All about Rebar Sizes and Bending Rebar

Rebar is the name given to concrete reinforcing steel, which is commonly used in construction of masonry, concrete buildings, and other structures. It is usually made of carbon steel and has ridges for better mechanical anchoring to the concrete. The purpose of the ridges is to aide in the placement of the load between steel and concrete. Tensile strength is provided by embedded steel reinforcing bars and compressive strength is provided by concrete. Combined, these two substances will prevent a block of concrete from crumbling. Remember the last big earthquake in Mexico City?  If you will recall, the new buildings collapsed, while the older buildings stayed standing. Only smooth and solid bar is used in the new buildings; they don’t use rebar. The concrete did not receive any strength of compression.

Rebar is measured in fractions of one-eighth increments and ranges from #3 bar up to #18 bar. Therefore, #4 bar measures 4/8 or ½” in diameter and #8 bar is 1” in diameter. You can get rebar in different grades and specifications. These vary in yield strength, ultimate tensile strength, chemical composition, and percentage of elongation.

The minimum yield strength of the bar is equal to the grade designation. Here are some examples: Grade 40 rebar minimum yield strength is 40ksi. Grade 60 minimum yield strength is 60ksi. Grade 75 minimum yield strength is 75ksi. Grade 60 rebar is generally used for concrete construction. The most common choice used in residential areas like sidewalks and similar low stress concrete applications, is grade 40. For heavy duty concrete products such as power plants or bridges, we find grade 75 used.

There must be a method for the fabrication of these bars as rebar normally comes in twenty foot length sticks. Meaning the bending and shearing must conform to the engineers design. A wide variety of sizes are available for rebar shears and benders. Bar size and capacity are related, as previously stated. When a residential concrete mason is working with #3 thru #6 bar, he usually sources a machine that is capable of cutting and bending #8 bar. The reason for this is that occasionally more than one bar at a time must be processed in order to speed up production. Having extra capacity can be very helpful.

When selecting the equipment for heavy concrete construction, it is very important to determine the capacity correctly. When you are building bridges and buildings, you must use heavier grade steel, larger diameter bar, and heavier capacity machines. Your supplier should be experienced and knowledgeable enough to help you choose the right capacity machine for the job.