How to cut rebar?

Do you know how to cut a rebar?

According to Aaron Barnett of BangingToolbox: Steel reinforcement bar, or rebar, is used in almost every modern concrete construction formation. It’s vital for making concrete reinforced and strong making otherwise brittle concrete able to take heavy loads.

If you plan to use concrete and rebar in your next project, you need to know how to cut it properly, along with the right tools and methods to save time and money.

What are the benefits of  rebar?

• Strengthen concrete. Concrete is only strong against compressive stress. Rebar is used in creating reinforced concrete that can withstand tensile stress better than concrete alone.
• Makes thinner concrete slabs possible. Using the right amount and arrangement of rebar means that concrete structures can be made thinner for the same overall strength to reduce weight and decrease concrete costs.
• Prevents cracking. Rebar can help restrain concrete’s tendency to shrink and grow due to thermal expansion to prevent cracks.
• Extends the life of the structure. Having a stronger concrete structure means that it can withstand the test of time and increases the probability that your structure will survive natural calamities such as earthquakes and hurricanes.
• Cost-efficient. The benefits stated above ultimately mean a lot of cost-savings to be had by using rebar. Thinner and stronger concrete brings down construction costs while preventing cracks keeps maintenance and repair costs low.

What is the difference between standard and high-tensile bar?

In concrete construction, there are two types of reinforcement bars one called high tensile rebar. This type of rebar is used when more strength is needed in reinforced concrete which standard rebar cannot provide. Since it’s stronger, high tensile rebar is also more difficult to cut.

How to know if the rebar is high-tensile?

High tensile rebar can be distinguished by looking at its transverse ribs. High tensile rebar has two sides without ribs at regular intervals while standard rebar has them along its entire length.

What are the challenges of cutting rebar?

Since rebar serves an essential role in reinforcing concrete so that it can take larger loads, rebar needs to be cut properly in an economical way.

The steel that rebar is made out of is also really tough and hard and can cost a lot when it comes to blade replacement if you only use conventional rebar cutting tools like an angle grinder.

What are the factors to consider when cutting rebar?

Time and speed

Some methods of cutting rebar will take a longer time than others.

If you’re against the clock and need to cut rebar quickly, using a dedicated rebar cutter or a cutting power tool will help speed up the process.

Rebar size

Home construction, landscaping, and DIY cutting work typically use #3 rebar. This size of rebar is easy to cut with a lot of tools.

Meanwhile, thicker rebar is used for commercial and industrial applications and requires specialized equipment to cut.

Rebar quantity

Large amounts of rebar can take longer to cut even with the necessary tools.

It’d be beneficial to cut high volumes of rebar in batches to maintain speed and consistency.

Cutting quality

Of course, speed is not the only thing that matters. Rebar also needs to be cut well and at an exact size in order to not compromise structural integrity. Power tools give a better-quality faster cut than hand tools.

Tools available

The method you’ll be using to cut rebar will depend largely on the tools you already have.

Not everyone has a dedicated rebar cutter, but you can also strive for similar results with a chop saw, rebar bender, or even a bolt cutter for steel mesh.

Manpower

Some tools require two or more people to operate and maintain efficiency.

Keep this in mind as it can sometimes be a limiting factor.

1. Cutting with a portable rebar cutter

Cutting with a portable rebar cutting tool can be done anywhere as long as it is free from sensitive objects that can get damaged by flying debris. It is best to do this in an empty room or a small space so that nothing can get damaged and you will also have somewhere to store the cut rebar.

Remember to wear eye protection and other protective equipment.

How to cut with a portable rebar cutter?

1. Mark the bars on where you want to make the cut.
2. Insert the rebar into the jaw of the cutter.
3. Pull down on the trigger to begin cutting. A blade will begin to protrude from the jaw, cutting the rebar.
4. Store cut rebar aside and repeat until all rebars are cut. 

2. Using a rebar cutting machine

Prepare a small empty area to set up the rebar cutting machine. This is done to avoid any work-related injuries and provides a space to store cut rebar. Once you’re set, plug the machine into a stable power source.

How do you use a rebar cutting machine?

1. Mark the bars on where you want to make the cut.
2. Insert the rebar into the jaw of the machine.
3. For safety, stand about two feet away from the machine.
4. Pull down on the long lever or cutting clutch to begin cutting. A blade will begin to protrude from the machine, cutting the rebar.
5. Store cut rebar aside and repeat until all rebars are cut. 

3. Using an angle grinder

A 4 or 4 ½ inch angle grinder is suitable for most rebar-cutting jobs. remember to replace the cutting blade, for rebar, with ones specifically made for cutting metal. Better yet, go with a diamond blade that lasts longer and produces cleaner cuts.

Additionally, you will need a sturdy base such as a workbench or a long wood plank, as well as a vise or clamp to secure the rebar in place. This guide shows you how to do it. Sparks will fly while cutting rebar so remember to wear appropriate safety gear [1] such as a mask, gloves, and goggles.

Cutting a rebar with an angle grinder

1. Measure out and mark where you want to make the cut.
2. Secure the rebar in place using your foot or a clamp jig made of two pieces of wood.
3. Turn on the angle grinder and fully cut through the rebar.
4. Use the angle grinder to buff out and flatten skewed sharp edges.

Here’s a more detailed guide of using an angle grinder.

4. Cutting a chop saw

Using a chop saw instead of an angle grinder removes the need for as many blade changes or a clamp to secure the rebar in place.

When cutting, remember to use the appropriate blade and wear the proper protective equipment.

Cutting a rebar with a chops saw

1. Measure out and mark where you want to make the cut/s.
2. Place and secure the rebar on the locking jig. Depending on the size, you can also cut multiple pieces of rebar at once.
3. Start the chop saw and allow the blade to speed up.
4. Pull down on the handle and lower the blade towards the bars until they’re completely cut.
5. Lift the blade and turn off the saw before removing the rebar from the locking jig.

5. Using a cutting torch

Using an oxyacetylene or plasma torch is inefficient for large jobs, but is sufficient for most non-industrial scale applications. You’ll need a clear and empty space as well as a stable work area for clamping down the rebar.

Lastly, you’ll need a steel pipe to help bend the rebar. Cuts from torches are typically uneven and may need some post-processing work [2] to make them viable.

How do you cut rebar with a cutting torch?

1. Secure the rebar with a grip or vise.
2. Heat the rebar with a torch until it is malleable enough to be bent.
3. Use a pipe to bend the rebar repeatedly until it breaks loose. Re-heat the rebar once it starts to feel rigid and cool.

6. Using a bender

When using a manual rebar bender/cutter, it’s important to make sure that the tool is mounted on a sturdy base such as a heavy wooden plank or bolted down on the floor. This ensures that the tool stays secure during operation.

Cutting should be done in a small empty space with a lot of clearance around the machine’s jaw since cut pieces can sometimes fly off. Remember to wear protective equipment like gloves.

How to use the manual bender?

1. Measure out and mark where you want to make the cut.
2. Insert the rebar into the appropriate cutting slot at the jaw. A manual bender/cutter usually has separate slots for different sizes of rebar so be sure to select the right one.
3. Once in place, push down on the lever and apply force until the rebar is fully cut.

7. Using a bolt cutter

Cutting rebar with bolt cutters will only work on small steel bars such as steel mesh and not D12, D16, or D20+ bars.  Depending on the rebar, you may need an extra hand if it proves too difficult to cut alone. Remember to wear gloves and other protective equipment.

Here’s how to cut rebar with bolt cutters:

Cutting with a bolt cutter?

1. Measure out and mark where you want to make the cut.
2. Hold the bolt cutters firmly with both hands at the ends of each handle.
3. Place the jaws of the cutter on the rebar where you marked.
4. Make sure that you are cutting perpendicular to the rebar as cutting at an angle may cause it to dangerously twist or slide off.
5. With a firm grip, pull both handles together until it fully cuts the rebar.

Why you can’t use a hacksaw or reciprocating saw?

Hack saws use long and typically expensive blades that wear out rapidly for how much they’re worth. Being made out of extremely sturdy steel, cutting rebar with these saws will easily wear out and damage the blades even if you use the ones specifically made for cutting steel.

It’s technically possible to go about cutting rebar with Sawzall but only as a last resort as it will take a long time.

Different saw types have significant uses on each of their own.

What is the best tool for cutting and bending rebar?

The easiest way to cut rebar and the most common tool for this task is a manual rebar bender with an included cutter.

It’s easy to set up, is portable, and only needs a single person to operate, and will not require blade replacements.

You don’t need to plug it into a power source nor is it high-maintenance.

It can cut through common rebar sizes from #3 all the way to #5 and can bend the rebar to as much as 180 degrees without noise or producing sparks.

The best option however is to invest in a portable rebar cutter, to save your body from wear and tear from constant bending.

Do’s and don’ts when cutting a rebar

When cutting rebar, it’s important to make sure that there is enough space in your work area to fit the long lengths of rebar (Typically outside). 

Rebar is typically sold in 20-foot lengths, so your workspace must at least have the same dimensions. Always stay an appropriate distance away from the cutting jaw of a rebar cutter. Lastly, wearing proper personal protective equipment is a must.

Debris and sparks can come flying as you cut rebar with only an angle grinder and can injure or blind you if you don’t wear the proper PPE.

Cutting rebar may not always be easy.

 But is nonetheless essential and can be easy with the right tools. Fortunately, there is a myriad of tools you can use – from the benders to dedicated rebar cutting machines. You must choose the one that is more available to you as well as one you’re more comfortable working with. 

Cutting rebar is hard, but not impossible. With the right tools and knowledge, you can be just like Magneto – bending and cutting rebars at your will or with only the push of a button.