Q&A for How to Bend and Cut Rebar

No. Direction of the bend does not change the integrity of the bar. Repeated bends at the same point, however, will weaken the metal.

Yes, rebar is very soft iron and does not crack easily. It can be straightened and then re-bent.

That depends on the design. Basically, it varies from 1 to 4% of rebar in concrete quantity.

A bench vise is a very handy tool to hold rebar while bending and cutting. However, due to the forces involved in bending rebar, you have to make sure the bench vise is securely mounted to a heavy object/workbench. An added benefit of using a bench vise is that you can strike the rebar with a hammer to help create more precise bends.

There are many types of rebar. Typical rebar in North America is referred to as "carbon steel rebar" and is excellent for reinforcing concrete; however, its biggest weakness is that it rusts and corrodes quickly (inside a typical concrete slab, this isn't a big big issue). There are many other types, including coated rebar, such as epoxy-coated (often seen in highway projects due to its longevity and improved inhibition of rust) and galvanized rebar. For specialty projects, there are even rebars made of stainless steel and even non-metal-reinforcing rods such as glass-fiber-reinforced polymer bars (GFRP), which can often be found in landscaping and brick/block work to serve as pins.

Some products come with instructions that indicate the size of rebar to be used, but in most cases a structural engineer is needed to complete a site-specific design for you. Structural engineers spend years in school learning how to calculate the size, spacing, and layout of reinforcing steel within structural concrete. Most projects require a building permit and a structural engineer.