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How to Use an Angle Grinder to Cut Metal Perfectly and Precisely?

how to use an angle grinder to cut metal
Written by Brent Butterworth
Last Update: May 8, 2023

Modern power tools have been around the commercial and DIY fields since old-school tools started losing their appeal. When all you want is cut hard, stubborn metal, a more powerful alternative than our ancestors’ favorite hacksaw should be the first thing you need. My favorite is an angle grinder because I’ve found it useful many times over different types of saws. If my words do interest you, I tell you, my friend, to read this article; so you become fully aware of cutting metal with angle grinder as you finish reading this.

Before I give you my explanation of the task, I would like you to read how the machine works because that’s what will help you throughout the process.

Understanding the Mechanism of an Angle Grinder

Angle grinders are a common feature in any hardware store. You need to select the appropriate size for different task levels. Many people usually settle for the 4” grinder that is powered by an electric motor of between 5-9 amps. This size aptly tackles the daily grinding and cutting needs of most types of metals.

A typical angle grinder is versatile. It easily handles wheels and accessories of different configurations. It comprises a handle, a spindle washer, and a protective cover. The spindle washer and nut is what hosts all types of wheels and discs you require for your different metal works.

How to Use an Angle Grinder to Cut Metal?

How to Use an Angle Grinder to Cut Metal

Before you start cutting sheet metal with an angle grinder, you need to have the correct tools and accessories. Therefore, you should prepare the project metals and follow the steps listed below. You understand that different angle grinder models operate differently. As such, follow the manufacturer’s instructions before you commence your project.

1. Gather the Required Tools

Perhaps the first step before you initiate your metal cut is to ensure that you have all the necessary tools for the work. You may require the following tools to make your job run smoothly:

  • An angle grinder
  • An appropriate power source.
  • Long power cable
  • Earmuffs
  • The correct metal disc
  • The metal material you intend to use
  • A C-clamp – to support and clamp your project metal
  • A shop drawing or the work template/sample

2. Gather Your Safety Tools

At this juncture, you have everything you need for the project. However, you still require appropriate personal protection gear before you commence on how to use an angle grinder to cut metal. As a minimum, you need the following safety gadgets when you:

  • Eye goggles – to prevent sparks from hitting your eyes or blinding you.
  • Safety boots – to protect your feet
  • Overall or tightly fitting cloth – to avoid fabric entangling the tool or power cord.
  • Gloves – to protect your fingers and hands
  • Secure floor –to prevent accidental falls. Working area should be dry and free from litters, water spillages, and obstacles.

3. Prepare Your Grinder

Now, set your disc into the grinder. You can do this by opening the spindle, inserting the correct metal disc and fastening the spindle nut in place. Ensure you have all your protective gadgets on and the tool is unplugged out of a power source.

4. Mark the Cut

Now lay the metal and clamp it secure on the worktop. After setting the disc and testing it, you should then outline the design you want to cut from the metal. You do this by laying the work metal on the worktop, using a scratch awl.

If the cut is a straight line, mark the two ends of the line then etch a scratch along the line. If the cut is a pattern or zigzag, outline the different bends the design takes, etch out the straight points with an awl and highlight the entire pattern.

5. Turn on the Machine and Start Cutting Carefully

With your job clearly outlines, now you are ready to switch on the angle grinder to begin grinding your metal. Power your carefully chosen angle grinder and hold the tool securely with both hands. While the disc is spinning, start with a smooth tap on the engraved line.

Hold the grinder firmly and start lightly to ensure that the tool doesn’t fly off your hand as well as it follows the set alignment accurately.

6. Don’t Just Change Directions Carelessly

In case you are not careful, there is a chance that the grinder may rev offline. To avoid this, move the tool back and forth along the set line. As you pile more pressure on the grinder to penetrate the metal plate or rod, you may notice that the grind isn’t as swift as during the initial stages.

However, continue the procedure until you penetrate the entire thickness of the plate. Carry on with this movement until you reach the other end of your marked outline. Avoid instantaneous changing of the grinder direction.

7. Finish the Cut

You have successfully cut through your metal sheet. You, however, will notice that the cut edges are still sharp and dangerous to handle. The grinder can still make good on the rough cut.

Simply remove the disc and insert a 40-grit flapper on the wheeler lock instead. Run the accessory along the edge of the newly cut line. It will smoothen the sharp edges. Thus, you got yourself familiar with one of the many uses of an angle grinder.

Additional Tips for Various Metals

After finishing, let your tool cool down for a few hours before using it again.

Just like bench grinders, angle grinders can perform an assortment of cuts on different types of metals. These materials include hard steel, sheet metal, and other metals. Hard metal needs secure fastening and a diamond disc to cut quickly.

Cutting and grinding a metal plate can be quick and fun with an angle grinder. However, note that a power tool and certainly an angle grinder is powerful and dangerous. You need to exercise all necessary precautions while using it.

Read all the manufacturer’s instruction on how to use an angle grinder to cut metal before you start on your project. This step will help keep you out of the harm’s ways while ensuring that you enjoy a long and trouble-free experience from your power tool.

FAQs:

1. What is the correct angle for grinding?

Ans. Maintain a 20 to 30-degree angle between the grinder and the surface for surface grinding. Make sure the blade guard is positioned at the back towards yourself.

2. How deep can an angle grinder cut?

Ans. A 230mm electric angle grinder can cut up to 70 mm in depth. You can use a 125mm angle grinder for 38mm deep cuts or a 115mm to cut up to 30mm deep.

3. Do I push or pull an angle grinder?

Ans. Don’t try to force the wheel through the workpiece. The right way to minimize friction and force is to allow the wheel to pull itself through the piece. This also helps extend the lifespan of the grains.

4. Can I use an angle grinder as a Sander?

Ans. You need to attach an abrasive flap disc to the angle grinder to turn it into a sander. This allows you to use the grinder for sanding welded joints, metal, and wood.

5. Can I cut wood with an angle grinder?

Ans. An angle grinder has the capability and strength to cut woods. However, it’s not the best option for the job, so you should pick another tool.

About the author

Brent Butterworth

A Professional Woodworker & Custom Furniture Builder

Brent lives in Wisconsin and is a woodworker, custom cabinetmaker, interior consultant, and a freelance writer who got the opportunity to write several magazine articles for different publications on home improvement and woodworking. He’s always amazed at the depth and breadth of woodworking all over the globe, and feels proud to be a part of this great effort. Brent has built everything one can imagine, from unique art furniture to different types of home furniture to canoes and even a sailboat.

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