This includes the angle grinder, which can be used to do everything from smoothing rough edges to removing rust from plate metal. But perhaps most importantly, you’ll often find yourself using this tool to slice through metal.
Accomplishing this task is easier said than done, though, which is why we’ve created this beginner’s guide to cutting metal with an angle grinder. Herein, you’ll learn the proper steps for efficiently and safely going through the process.
What Type of Metal Cuts is an Angle Grinder Suitable For?
Generally speaking, angle grinders are primarily used to efficiently make rough cuts through small- and medium-gauge metal stock. To that end, they are often considered to be a faster, less labor-intensive alternative to a manual hacksaw.
In this capacity, most standard angle grinders (equipped with the proper disc blade) can slice through bolts, rebar, and sheet steel with relative ease.
When it comes to using an angle grinder on sheet metal, a skilled user can accomplish a fair number of cuts. This includes standard through cuts across the entire length or width of a sheet, or even punch out cuts within a sheet’s interior.
Cutting metal with an angle grinder tends to cause the unit to buck slightly, though, so the task should only be done professionally after engaging in an ample amount of practice.
Alternatively, you can consider using metal shears or nibblers.
How to Use an Angle Grinder to Cut Metal
With that out of the way, let’s dive into how to actually get the job done.
Step 1: Gather Equipment and Materials
Before you can start cutting metal with an angle grinder, you need to take some time to gather all of the proper equipment. Naturally, this includes a working angle grinder unit (see my recommendations), as well as a cutting disc that fits the unit. You should also get some C-clamps.
You’ll also want to find a location to safely make your impending cut. This surface should be large enough for you to work safely.
At this stage, you should also ensure that you are following all of the right procedures regarding PPE. Metal cutting with an angle grinder will send out sparks and metal debris, so it is essential that you wear eye and ear protection. You should also be wearing snug-fitting clothing that is durable enough to withstand sparks. The same goes for your boots, which must be rated to withstand welding-class wear and abrasion.
Step 2: Equip Disc and Mark Cut Lines
After all of your work and safety equipment has been gathered up, you are ready to begin the cutting preparation process. This should start with you selecting the right type of cutting disc blade based upon the type of cut you intend to make and the type of metal you are cutting into.
In most cases, a standard-width disc cutting blade should suffice. However, if you are working with an extra-dense metal, you may want to pull out a diamond-edged blade for good measure.
Once you’ve picked out the right disc blade and installed it, you’ll want to take some time to mark out your intended cut line. This is even the case if you intend to cut directly through a metal workpiece. To do this correctly, you’ll want to grab a piece of chalk and your preferred measurement tool.
From there, you can mark out your intended cut lines and ensure that there are as straight and true as needed.
Step 3: Clamp Down Metal Piece
Once you’ve marked your intended cut lines, be sure to clamp down your workpiece. This is a crucial step that many first-timers forget, but it is essential for preventing your workpiece from scooting out from beneath your blade in a dangerous manner.
This is primarily needed when working with loose sheet metal and rebar. To that end, C-clamps can be used to successfully secure most regular-sized metal workpieces prior to cutting.
Step 4: Perform the Cut
Finally, with all of your preparations address, you are ready to don your PPE and grab your angle grinder.
Once the unit is plugged in, you can turn it on and wait for the blade to reach full speed. Then, you’ll want to slowly lower the active blade onto the start of your intended cut line. At that point, you should apply some pressure. At this point, sparks and some metal debris may begin to fly.
Once your cut is established, you can continue working through it.
If you are working with thin stock, this can often be done in 1 to 2 passes. However, a thicker material like rebar may require 3 to 4 passes in order to successfully cleave it apart.
Mistakes to Avoid, Tips & Tricks
Many of the most common mistakes made when using an angle grinder to cut metal are related to the tool’s safe operation and implementation.
For example, many amateur fabricators make the mistake of using their free hand to secure or balance their metal workpiece as it is being cut. This is very dangerous and is not advisable in any situation. Not only does this put your hand in line with an active saw blade, but it may also cause that hand to be injured by output sparks and debris.
Also, even professional fabricators occasionally attempt to force their angle grinder’s disc blade through a cut. This is also not advisable. If you are facing more resistance than your blade can handle, you may need to switch to a more abrasive blade with a greater cutting capacity. Alternatively, you may try making several passes on the same cut line, rather than trying to apply direct force into the cut.
When you get down to it, the steps for cutting metal with an angle grinder are not all that complicated. However, that doesn’t mean that any old DIYer can learn to do it properly on their first try.
Instead, like all fabrication work, metal cutting with an angle grinder requires practice, not only with this power tool but also with a variety of metal types and gauges.
Now that you know the basics, you too can begin to master this process.