How to Use an Angle Grinder | 3 Key Tips to Grind Like a Pro
We got our Pro team together to give you some tips on how to use an angle grinder from basics to some advanced techniques and shortcuts. Angle grinders are controlled by either a trigger, paddle, or a switch. They spin a disc at an incredible rate of speed for the express purpose of sanding, grinding, or cutting. The many uses of an angle grinder make it a versatile tool used by a wide range of professionals. With so much flexibility at your disposal, the angle grinder also has a steep learning curve compared to many other tools.
- Wear proper protection
- Match the accessory to the grinder
- Face the debris away from your body
- Maintain the proper angles
How to Use an Angle Grinder
Tip #1: Protect Yourself Before You Wreck Yourself
Before you use an angle grinder, you’ll want to grab some personal protection gear. The reality of the angle grinder is that it’s a loud tool that kicks a whole lot of debris around. Plus, you’re not always grinding or polishing. Oftentimes, the job entails cutting. If you get sloppy with a cutting wheel or simply have bad luck, that wheel could turn into high-speed shrapnel.
For these reasons, you’ll do yourself a favor if you grab some hearing protection, long sleeves, gloves, and something to shield your entire face. You don’t want to take a hot shard of cut-off wheel to the moneymaker, after all.
Pro Tip: Having a cutting wheel fly apart on you at 10,000 RPM is no joke. There’s nothing you can do when it happens. As a result, you want to always wear a full face shield when using a cutting wheel—even when using a guard. Grinding and using a flap disc doesn’t typically present the same level of danger, so the guard and adequate eye protection are often enough.
Tip #2: Your Accessories Need to Match the RPM of the Grinder
When attaching your wheel, disc, or cup, check the manufacturer’s specs. The max RPM on the accessory should meet or exceed the max RPM of the grinder you plan to use. If the rated speed of the accessory is lower than your grinder, you run the risk of the wheel flying apart.
Tip #3: Position the Tool Properly and Watch Those Sparks!
Angle Sparks Away from Your Body
Because angle grinders quickly remove lots of material, lower the risk as much as possible by positioning the tool properly. Different applications and attachments call for different angles. Ensuring sparks and debris fly away from your body reduces your chances of getting injured. Your work clothes will last longer, too!
Surface Grinding and Flap Discs
For surface grinding, use the flat part of the wheel, maintaining a 20°-30° angle between the tool and the work surface. Position the blade guard at the back towards your body. Use a smooth back and forth motion to guide the flap disc over the material. Let the wheel do the work, but feel free to apply enough pressure to ensure you’re being productive.
You should tackle cutting straight on since you want to use the edge of your wheel to cut into the work surface. Be careful not to bend the cutting wheel in any direction. In this mode, the guard always goes on top to protect you from debris. Wearing a face shield also protects you against premature disc failure. And remember—if the guard isn’t between the cutting disc and your face—move it until it is.
Light Grinding or Sanding
For sanding applications, hold the tool at a 5°-10° angle to the work surface. For pretty much all grinder applications, apply only minimum pressure. You want to allow the tool and the wheel to do the hard work.
Additional Pro Tips on How to Use an Angle Grinder
- Before applying the grinder to the work surface, allow the tool to reach full speed. You’ll do a better job of keeping your cuts and grinds consistent.
- For grinding and sanding applications, keep the tool moving so as to avoid gouges just like you do with a sander. You’ll end up with much smoother and more professional results.
- Some grinders have lock-on switches. These have the potential to come on whenever they receive power. That means that if you swap out a battery, attach an extension cord, or reset a breaker, you want to make a habit of turning the grinder off first. Some grinders have a built-in “zero voltage” safety to avoid kicking on automatically, but not all do. This is a great safety feature.
- Make sure everything stops spinning before setting the angle grinder down. Even a lightly spinning blade can damage work surfaces and grab loose clothing. A braking grinder (grinder with an electric or mechanical braking system) really helps avoid these problems.
- Occasionally, you’ll want to remove the guard when it gets in the way. Many Pros have at least one story about a cutting wheel shattering. Most shrouds rotate to make life a little easier. Most of these tools spin at over 10,000 RPM. In general, you want to keep that guard on no matter what!
If you’ve got any tips or tricks on how to use an angle grinder, feel free to leave your input in the comments section below!