How to Cut Rebar: Choosing the Right Tools & Techniques

Apr 19th 2024

Empire Abrasives: Tools and Techniques to Cut Rebar

Reinforcing bar, aka rebar, is a steel bar used to reinforce concrete and masonry structures by enhancing their tensile strength. In various construction projects working with this material, these steel bars will need to be cut or resized to fit the unique plans for the structure. Cutting rebar the right way, with the right tools, is the key to preserving the structure’s integrity, and for keeping you safe in the process.

In this guide, we’ll go over the different tools for cutting rebar and provide instructions on how to cut rebar by hand or with different machines.

Safety First

We have to start with safety here, because of its importance when cutting rebar. Serious injuries can happen due to sharp edges, flying debris, and the potential for kickback. Before attempting to cut rebar, take a few minutes to set up your safety measures:

  • Wear appropriate (PPE) at all times. This includes safety glasses/goggles, cut-resistant work gloves, sturdy work boots, and hearing protection.
  • Remove anything flammable from the work area, especially if you’re working with a torch or your tool has the potential to create sparks. It is also a very good idea to have keep the area well ventilated when working with tools that produce sparks or fumes.
  • Always firmly secure the rebar in place with clamps, vises, or other restraints to prevent it from moving while cutting.
  • Keep a fire extinguisher nearby in case of sparks or fires.
  • Never work alone when cutting rebar. Have someone present who can assist in case of an emergency.

What is the Best Tool to Cut Rebar?

The best choice for a tool to cut rebar depends on several factors, including the project size, the diameter and grade of the rebar, portability, desired cut quality, and cost considerations. Below we split up the options between manual tools and power tools.

Manual Tools: Cutting Rebar by Hand

1 - Hacksaw

Traditional metal hacksaw with a long blade ready for rebar cutting projects

A hacksaw is a simple and inexpensive option for cutting rebar that you'll usually find in most workshops or garages. This technique is also the most labor-intensive way to do it, and best suited for thinner rebar that have smaller diameters.

To cut rebar with a hacksaw, start by clamping down the rebar securely, marking your cut line, then making steady strokes until the cut is complete. It can be a time-consuming process, but it's a good option for DIY projects where you want to save some money or when you don’t have the right power tools unavailable.

2 - Bolt Cutters

Blue bolt cutters trimming rebar to size for building reinforcement

Bolt cutters are powerful manual cutters capable of quickly snapping rebar with clean cuts. It requires much less effort than using a hacksaw. While bolt cutters are great for cutting rebar with smaller diameters, they won’t be suitable for cutting thicker pieces.

To use bolt cutters for cutting rebar, position the rebar between the jaws of the cutters and apply steady pressure to the handles until the rebar is severed. For larger rebar sizes, you may need to make multiple cuts from different angles to completely sever the bar. If that doesn't work for the larger bars, you may have to finish it off with a different option.

3 - Chisel and Hammer

Classic tools for rebar work: a sturdy hammer and sharp chisel

This isn’t a common way to cut rebar, but can be handy for making small adjustments or when you're working in tight spaces.

To cut (and then snap) rebar with a chisel and hammer, start out by securing the rebar to a sturdy surface and then mark your cut line. Place the tip of the chisel on the marking and continue to firmly strike it with your hammer. Rotate the rebar and continue chiseling around the entire rod until the metal weakens enough to break. Then, bend the rebar back and forth until it snaps along the scored line.

Power Tools: Advanced Methods for Rebar Cutting

4 - Angle Grinder

Sparks fly as an angle grinder cuts through steel rebar for concrete reinforcement

An angle grinder is a versatile power tool used to grind and cut metal and various materials, including rebar. They are portable and ideal for quick, rough cuts. Using an angle grinder requires proper safety measures due to the high-speed rotation of the cut-off wheels and the potential for kickback.

To cut rebar with an angle grinder, secure the rebar in place and equip the grinder with a durable cutting disc for metal. Hold the grinder firmly with both hands, keeping the disc perpendicular to the rebar. Apply steady pressure and let the disc do the work. Avoid using excessive force that could damage the discs.

5 - Circular Saw with a Diamond Blade

Cutting rebar with a high-speed circular saw equipped with a diamond blade

A circular saw equipped with a diamond blade is an efficient and accurate cutting method for rebar. The diamond blade's abrasive edge easily slices through steel, providing you with clean and precise cuts. However, not all of these saws are created the same. Always check to make sure you have a saw specifically designed for metal cutting and to follow all safety precautions to prevent kickback and flying debris.

To use a circular saw for cutting rebar, first secure the rebar in a stable position. Set the saw's blade depth to slightly more than the rebar's diameter. Align the blade with your cut mark and start the saw, allowing it to reach full speed before making the cut. Apply firm, steady pressure and let the blade do the work, avoiding excessive force.

6 - Reciprocating Saw

Working holding a reciprocating saw which can be used to cut rebar.

A reciprocating saw, also known as a recip saw or a Sawzall, is a very convenient tool for cutting rebar. They are great in tight spaces or when portability is your top priority. The best reciprocating saw blades to cut rebar effectively are bi-metal, diamond-grit, or carbide tipped blades designed for metal cutting.

To cut rebar with a reciprocating saw, first secure the rebar in place. Install your reciprocating saw blade into the saw and set it to the straight reciprocating motion. Position the blade on your cut line and apply steady pressure while allowing the blade to do the work. For thicker rebar, you may need to make multiple passes from different angles.

7 - Chop Saw

Heavy-duty chop saw cutting rebar efficiently on a construction project

A chop saw, also known as a metal-cutting saw or an abrasive saw, is designed specifically for cutting rebar and other metals. It uses very sharp chop saw blades (large and very durable abrasive cutting discs), which delivers precise, clean cuts with minimal effort. Chop saws can be expensive, but they're an excellent choice for high-volume rebar cutting like construction sites.

To cut rebar with a chop saw, first secure the rebar in the saw's vise or clamping system. Adjust the fence to the desired cut length and ensure the blade is properly aligned. Set the appropriate blade speed, based on the manufacturer's instructions, then make the cut by lowering the blade onto the rebar with steady pressure.

8 - Portable Rebar Cutter

Portable hydraulic rebar cutter providing a clean cut through construction steel

A portable rebar cutter is a handheld, hydraulic-powered tool designed specifically for cutting rebar to size. It is conveniently portable and one of the easier tools to use. Unlike most of the other options, portable rebar cutters don’t produce sparks or flames, making it a safer option in certain environments.

To operate a portable rebar cutter, first position the rebar into the machine’s cutting jaws and check to make sure it is properly aligned. Activate the hydraulic mechanism, which is usually done by squeezing a lever or trigger and apply steady pressure until the rebar is severed.

9 - Hydraulic Rebar Cutting Machine

Industrial hydraulic rebar cutting machine in use at a construction site.

For large-scale construction projects or industrial projects where large volumes of rebar need cutting, a dedicated rebar cutting machine is usually the best option. These machines, often powered by electricity or hydraulics, can effortlessly slice through multiple pieces of rebar at the same time, with clean and accurate cuts across every bar in the batch. You’re not going to find this in many DIY garages. They are very expensive pieces of machinery found in large fabrication shops or owned by professional contractors.

To operate a hydraulic rebar cutting machine, load the rebar into the machine's clamping system. Check that all of the rebar is properly aligned and supported. Consult the manufacturer's instructions for setting the cutting parameters, such as blade speed and hydraulic pressure. Once the settings are dialed in, initiate the cutting cycle and allow the machine to do the work, producing clean, consistent cuts across all the rebar pieces.

10 - Torch:

Worker using a blowtorch for precision cutting of rebar on a construction site.

Using a torch, such as an oxy-acetylene or plasma cutting torch, is another method for cutting rebar. The extremely high heat melts through the steel, making a fast cut of the rebar. It is particularly useful for larger diameters or where precision is not a primary concern. However, the blowtorch method requires specialized equipment and training to operate safely and effectively.

To cut rebar with a torch, first secure the rebar in a stable position and clear the area of any combustible materials. Follow the manufacturer's instructions for setting up and igniting the torch, adjusting the gas flow and pressure as needed. Maintain a consistent distance and angle between the torch and the rebar, moving the torch along the desired cut line. Proceed with caution, as the intense heat can cause the rebar to warp or deform if not properly controlled.

Tool Selection Factors

When deciding on a tool for cutting rebar, weigh the following factors:

  • Project Size: From small home improvements to large construction sites, the scale dictates the tool's power and endurance.
  • Rebar Diameter and Grade: Thicker, higher-grade rebar demands more robust cutting tools.
  • Portability Requirements: On-site adjustments may require portable solutions.
  • Cost and Accessibility: Evaluate the cost against the frequency of use and availability.
  • Desired Cut Quality: Choose tools that provide the required cut finish, from rough to precision cuts.

How to Cut Rebar: Step-by-Step Guide

Even though we explained the process for cutting rebar above for each tool, we will recap the basics you’ll follow for each option.

  1. Measure and mark the desired cut location on the rebar.
  2. Secure the rebar using clamps or a vise to prevent movement during cutting.
  3. Put on your personal protective equipment, including safety glasses, gloves, and sturdy footwear.
  4. Set up your chosen cutting tool according to the manufacturer's instructions.
  5. For power tools, start with a lower speed setting and gradually increase as needed.
  6. Apply firm but controlled pressure when cutting, and avoid excessive force that could bind or damage the tool.
  7. Allow the tool to do the work, and avoid rushing the cutting process.
  8. Once the cut is complete, carefully remove any sharp edges or burrs. You may find it easy to grind the burrs down with an angle grinder wheel or flap disc.

Making the Right Choice for Your Project

Whether you choose to cut rebar by hand with a manual tool or slice through the metal with a power tool, understanding the characteristics and applications of each option will help you make the right decision for how you should cut rebar. Always prioritize safety, and consider the specific needs of your project.

Remember that Empire Abrasives is your go-to online resource for quality cutting tools and expert advice. If you're unsure about the right tool or method, don't hesitate to consult with our abrasives professionals. They are available during normal office hours by phone, email, or website chat. In the off-hours, you can leave a voicemail or send an email that will be returned the next business day.