bending rebar

What Goes Into Bending Rebar?


Bending rebar can seem like a simple process, but getting the perfect bend every time requires more than just good technique. It also requires knowing exactly what you’re doing and why you’re doing it that way.

This article will help you learn everything you need to know about bending rebar to get the perfect bend every time you bend it!

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What is rebar?

Rebar is a common term for reinforcing bar, which is a metal bar used in concrete construction. Most rebar is made from steel, and it is used as a sort of skeleton inside the concrete. When it’s bent into shape, the rebar reinforces other materials by providing them with greater strength and stability.

Think of those giant slabs of concrete that brace large structures like bridges and skyscrapers in the architectural industry. Without reinforcing bars (rebar), they wouldn’t be able to support their own weight. Although there are different types of reinforcing bars, all are designed for structural purposes—and once you know how they work, bending them isn’t so hard after all!

What grade is standard rebar?

Using the ASTM grading spectrum, most rebar uses 40, 60, 75, 80, or 100-grade steel. This system uses a strength index to determine the grade. For example, ASTM grade 40 steel has a minimum yield strength of 40 ksi (kilopound force per square inch). To bend rebar, it must be a low enough grade of strength.

The standard weight of rebar depends on its grade and any added reinforcements. For instance, you might buy rebar that’s 4 feet long (120 lbs) with a 7/8 inch diameter. However, you can buy either heavier or lighter materials if necessary. If you’re working on a project where strength isn’t an issue, you can opt for one of the less expensive, smaller sizes.

Kloeckner Metals routinely stocks A615 grades 40 and 60 rebar in diameter 3/8” – 1 3/8” and No 3-11. Diameters typically go up by ⅛” per size. Each number, therefore, represents the numerator of the diameter when expressed in eighths. For example, rebar #3 is ⅜” in diameter. Rebar #4 is 4/8″.  Rebar #5 is ⅝”. And so forth.

While you can purchase rebar that is already bent, you can also bend rebar yourself for any project from at-home DIY to a major construction initiative.

What is rebar used for?

Rebar is a steel bar or mesh of metal wire used as a tension device in reinforced concrete and reinforced masonry structures. When used in vertical columns, it is often bent slightly so that it takes on an S shape. This allows it to be more easily placed in a single continuous pour of concrete around its circumference.

When subjected to extreme forces from winds or earthquakes, however, bent rebar can end up being pushed straight through rather than breaking along its length (which can happen if you’re not careful).

Why would you want to bend rebar?

There are a couple of reasons you might want to bend rebar. Most commonly, rebar is used in construction as columns to hold up brick buildings. And while it may seem like bending a metal pole into an arch would be tough, there are actually easy steps that anyone can do… or you can buy a rebar bending machine.

The one downside to bending rebar? It’s nearly impossible to remove once bent, so make sure you know where it’s going before you go through all that trouble!

How to bend rebar manually

Here are a few tips to get you started in your manual rebar bending adventures:

  • Be sure to wear personal protective equipment.
  • Do not heat the rebar if it is a non-weldable metal grade.
  • When you’re setting up for a bend, make sure that the bar is clamped tightly in a vise. You want your future bend to line up with the jaws of the vise. It’s also a good idea to put steel pipe around the free end of the rebar to help give you more leverage.
  • Since accuracy is key to perfect bends, use a set square to measure from one end of your rebar to find out how wide each section will be. Make sure it is perfectly straight.
  • To manually bend rebar you need two tools: clamps and a bar bender. The clamps hold everything in place. The bar bender helps guide and secure the metal while you hammer.
  • The next step is to mark where you want your first bend using chalk or a permanent marker.
  • Use slow even pressure to get the bend. Never smack the rebar with a hammer or other tool.

Unless you are working on a very small project, you or your team will not bend rebar manually. You’ll use a specialized machine.

How to bend rebar professionally using machines

When rebar is bent in order to reinforce concrete, it has to be done precisely. Rebar can become dislodged from concrete if bent too sharply, causing structural weakness. To prevent that issue and create cleanly formed bends every time, try using a rebar bender.

These machines typically include a mounted wheel that rotates against a fixed wheel attached to shafts of adjustable length. When you pull on the handles to bend rebar, it’s done under mechanical pressure rather than with your hands alone. With both wheels spinning at high speeds and exerting even force on all parts of the bar, you’ll get professional-grade results with consistency no matter what materials you’re working with or what kind of project you’re doing.

The advantage of using a machine for bending over by hand: Not only do these machines allow you to achieve better results, but they also eliminate much of the physical stress involved in bending bars by hand.

Since everything is done mechanically, there are fewer dangers associated with machine use —there are no exposed moving parts and there aren’t any exposed hands or fingers. You don’t have to worry about accidentally getting pinched while using one either, as long as you follow all safety precautions (and wear appropriate protective gear).

Since these machines are heavy-duty pieces of equipment, they’re not easy to move around without assistance. They’re also strong enough that multiple people don’t need to lift them during setup.

Contact Our Qualified Team Today

Kloeckner Metals is a full-line bar supplier and service center. To find out more about bending rebar for a commercial project, contact the team at Kloeckner Metals. We’d love to help you.

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Natalie Spira
Natalie Spira is Kloeckner's Acquisition Marketing Manager. Previously, she was the Founder and CEO of Fraction Marketing, a marketing agency providing fractional support to scaling startups with a focus on acquisition marketing and demand generation. Natalie holds a MBA from Tel Aviv University with concentrations in entrepreneurship and marketing and a BA in English from UCLA.
bending rebar
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