How to Use an Angle Grinder?

Being one of the most versatile power tools in the market, an angle grinder can do the job of many other tools—but only if you use it properly and follow the safety recommendations!

While operating an angle grinder is not really rocket science, there are different attachments and techniques required for each task: grinding, cutting, cleaning, polishing, sharpening, and so on.

We’ve created this guide to help you understand how to use an angle grinder, how to hold an angle grinder, and other tips to obtain the best results.

Let’s get started!

Getting ready

Angle grinder sanding metal

Even though angle grinders are beginner-friendly, there are still some precautions you need to take before using them to avoid accidents.

Wearing safety gear is essential for any of the tasks you can carry out with this tool. Removing excess material, which is basically what you’ll be doing, creates dust, debris, and sparks that can be dangerous. So, you’ll need gloves, safety goggles, hearing protection, and a dust mask or a full-face shield. For some tasks, you might also need to wear safety boots.

Once you’re ready, you need to secure the object or surface you are working on and hold it firmly in a bench vise or clamp it down to prevent dangerous slips.

You should also make sure you’re using the right attachment for your project, as there are specific designs for different materials and tasks.

Grinding

Grinding is the job angle grinders are best at, and with the right attachment, no material can stand in your way.

But first of all, you should be aware that you should never use a cutting disc for grinding. They’re thin and very likely to shatter under the pressure that’s required for grinding.

Now that’s out of the way, here is what you should do to start grinding:

  1. After securing the piece you’re working on, position the guard towards your body, keeping it between you and the disc.
  2. Hold the angle grinder firmly against the body of your workpiece and turn the tool on. If you hold the wheel into a sharp edge, it can catch on it and lead to kickback.
  3. Before you start, let the grinder come to full speed for smoother and better results.
  4. Using the flat part of the disc or wheel, guide the tool with a smooth back and forth motion at a 15°-30° angle.
  5. Don’t apply too much pressure and let the disc or wheel do the work.
  6. When you’ve finished, slowly lift the grinder off the surface and switch it off.

For grinding hard materials such as concrete, you might need to apply some pressure, but keep it light and consistent to reduce friction and avoid kickback.

Cutting

Angle Grinder

Cutting is another highly popular use of an angle grinder. You can cut metal, wood, concrete, stone, and even tile by following the same procedure:

  1. Mark an outline for the cut with a pencil or a sharpie both on the front and the back of your workpiece, and secure it with the front-facing up.
  2. Place the guard on top, between the disc or wheel and your face, to protect you from debris, and turn the grinder on.
  3. Wait for the tool to reach full speed and score around ⅛-inches deep around your outline, using the edge of the disc or wheel.

Using the face to cut will weaken the disc or wheel and make it even more prone to shattering.

  1. Turn the grinder off and flip your piece over. Secure it again, and repeat Steps 2 and 3 to cut from the back.
  2. Once you’re done, slowly lift the grinder off the surface and switch it off.

Some extra tips and recommendations to obtain the best results:

  • Mind the wheel and be careful not to bend it in any direction to get a clean cut.
  • Try to extend your cuts slightly past the corners to square them perfectly.

Cutting rebars, rods, and bolts

Angle grinders are quite convenient for cutting rebars, rods, and bolts quickly. Forget about using a hacksaw or any other tool, if you have an angle grinder this is what you should do:

  1. Put on your safety boots to protect your feet and position the guard between the tool and your body.
  2. Prop the long side of your workpiece and secure it. The short end of the piece is what’s going to drop away after the cut.
  3. Hold the cutoff disc perpendicular to your workpiece and turn the grinder on.
  4. Let the disc reach full speed and guide it through the piece by applying gentle pressure.
  5. Once you’re done, slowly lift the grinder off the surface and switch it off.

If you need to cut a bolt flush against the surface, particularly against concrete, we recommend that you grind it instead to avoid accidentally brushing the face of the cutoff disc against the surface.

Removing rust and paint

If you need to remove rust, dry cement, or old paint that’s flaking or chipping away, you can do it with an angle grinder, so you don’t risk damaging the material underneath.

There are various wire-brush wheel styles that you can use, depending on the cleaning task you need to carry out, so make sure you have the right one before you start.

The process is quite simple:

  1. Secure your workpiece and adjust the guard so it’s between the tool and your body.
  2. Make sure that the brush will be spinning away from you, as the wires on the brush tend to catch on the surface, causing the angle grinder to kick back.
  3. Turn the grinder on and let it reach full speed.
  4. Holding it firmly at a 90° angle, work the brush along the surface.
  5. When you reach a sharp edge or corner, the wheel should spin away from them to avoid kickback.
  6. After you’ve finished cleaning your workpiece, slowly lift the grinder off the surface and switch it off.

You might notice that using a metal cleaning wheel leaves a rough finish, so you might want to consider smoothing and polishing the clean surface afterward.

Smoothing and polishing

Man Angle Grinding

Believe it or not, there are attachments that help you fix the unwanted look of a surface and enhance its color, and bring life back to a dull material by polishing it.

Bear in mind that smoothing and polishing are very different tasks, so there are wheels specifically designed for each of them. Smoothing requires abrasive attachments, whereas polishing attachments are made of softer materials. Using the wrong kind of wheel will either make for an ineffective task or a damaged surface.

After you’ve sorted out the necessary wheel, you have to follow these simple steps:

  1. Secure your workpiece for stability to achieve an even finish.
  2. Place the guard between the angle grinder and your body, and wait for the tool to reach full speed.
  3. Position the tool at a 10°-15° angle over the surface and gently work it along the piece.
  4. Keep moving the tool for smoother and professional results.
  5. Once your workpiece is smooth and shiny, slowly lift the grinder off the surface and switch it off.

Smoothing and polishing require that to apply even pressure along the whole surface and that you move the grinder around constantly, so you don’t accidentally leave deep gouges and have to start again.

Sharpening tools

You can use your angle grinder to restore dull blades or rough edges on many garden tools, such as axes, lawnmower blades, shovels, and so on.

Here’s what you need to do to sharpen your tool with a grinder:

  1. Secure the blade and adjust the guard so it’s between the tool and your body.
  2. Make sure that the disc will be spinning away from you so no sparks come towards you.
  3. Match the blade angle with the disc and turn the grinder on.
  4. Once it reaches full speed, move the disc steadily in the direction of the handle, applying even, light pressure.
  5. Once you’ve achieved the desired edge, you can slowly lift the grinder off the surface and switch it off.

For a sharper and cleaner edge, we recommend giving the final touches with a mill bastard file or any other sharpening tool you have. Sharpening by hand always leaves a better finish.

Keep in mind that it’s very easy to overheat a metal blade using an angle grinder, making it more vulnerable to chipping and denting. If the metal becomes hot to the touch, you should stop immediately and allow it to cool down before continuing.

We recommend that you keep a bucket with water nearby to dunk the blade frequently to cool it off and prevent heat buildup. If you don’t want to be removing your tool from the vise that often, soak a sponge in water and run it across the blade frequently.

Removing mortar

To remove old mortar without damaging the bricks, you can use an angle grinder with a thick abrasive grinding disc.

The process is the same as grinding any other material, but you need to be more careful and patient as this task requires a high degree of control.

  1. Adjust the guard so it’s between your body and the tool, and start the grinder.
  2. Let the blade come to full speed and, with a smooth back and forth motion at a 15°-30° angle, make at least two or three ½-inch passes.
  3. Don’t apply too much pressure and stay, approximately, ⅛-inch from the brick to avoid damaging it.
  4. When you’ve finished, slowly lift the grinder off the surface and switch it off.

Since the angle grinder’s disc can easily fit between the bricks and reach the mortar joints and grind it at very fast speeds, you can completely forget about using a chisel and a hammer ever again.

 Conclusion

Thank you for reading our post on how to use an angle grinder! We’ve only touched upon some of the main uses of an angle grinder, but there are many projects that you can tackle with an angle grinder.

Now that you know how to operate it safely and efficiently, you’re ready to start grinding, cutting, cleaning, and sharpening. Just remember to wear your safety gear, read the manufacturer’s instructions and follow our recommendations!

Be sure to also check out our post on the best angle grinders to help you choose the perfect angle grinder for you!

Liam Weissman

Hello and welcome to PowerToolGenius! My name is Liam and for the last 9 years, I have worked extensively with various power tools and accessories. I have tested hundreds of different brands and models and understand the industry extensively and have been working with tools my entire life!

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