Before I get started I do want to say that you need to be careful when using an angle grinder to cut anything. If you have never used an angle grinder before, definitely do not use one to cut bricks. Trust me when I say that is a recipe for disaster. Aside from ladders, angle grinders are, in my experience, the most dangerous tool you can use for your DIY projects.
I also highly recommend wearing personal protective equipment before attempting any cut with an angle grinder. Now that I got that out of the way, let’s talk about what size angle grinder you need to cut bricks.
What Size Angle Grinder is Best?
If you’re looking to make easy clean cuts on your bricks, you should use an angle grinder that is at least 4 and 1/2 inches. 4 and a 1/2 in. should be deep enough to allow you to cut all four sides of the brick so that when you use a hammer to give it a tap, you end up with two clean pieces.
I’ve had a really good experience with Makita and their 4 and 1/2 in angle grinder. When I used to work at a masonry company, everyone in their mother used the Makita, which I think says a little bit in terms of the quality. I also wrote a guide on some of the best angle grinders, which should help you if you’re in the market for one.
That being said, here’s a video that shows the process from beginning to end.
Aside from the fact that this guy completely ignores his own safety and doesn’t even secure the brick, he does a good job of at least outlining his process. You can clearly see that he uses a four and a half inch blade to cut the brick and doesn’t have any issues with it.
In terms of a larger blade, I personally haven’t needed to use the 7-inch blade or the 9 inch blade, but I would imagine you would have a similar success using those to cut the bricks as well, and wouldn’t have to cut all 4 sides to get the clean cut you’re looking for.
Note: An angle grinder with a 4-1/2-inch diameter blade can cut roughly 2-1/4 inches deep, while a 9-inch grinder can cut about 4-1/2 inches deep. Use this info as a rough guide which size is right for you. The bigger the brick, the bigger the blade you need.
Now keep in mind that you should be using a diamond blade. They are durable, last long, and are just generally easy to use with any masonry material.
Also for the love of God, please make sure you’re wearing a mask because the dust particles from the bricks can cause damage to your lungs.
So are angle grinders my preferred way of cutting bricks? Absolutely not. However for simple projects where you’re abundantly cautious angle grinders could work. If you need to cut asphalt, check out our guide on how to cut asphalt with an angle grinder.