Illustration by Len Churchill; Photos by Rob Brown
The wide range of accessories available for angle grinders make them a “go-to” tool on the jobsite and around the home. They’re classified by the maximum diameter of the accessory they can accommodate, with the most popular grinder sizes being 4″, 4-1/2″ and 5″. You can purchase grinders in three power source options – corded, cordless and pneumatic. Some grinders have an on/off (a.k.a. slide or lock-on) switch, while others use a paddle switch. The paddle switch is integrated into the handle. Grip the handle and squeeze the paddle to turn the grinder on, release the paddle to turn it off. Some grinders with paddle switches also have a lock-on button. All angle grinders employ a lock nut and backing flange installed in different configurations to accommodate different accessories. The specific accessory to use with an angle grinder depends on both the type of material you’ll be working with – wood, metal or masonry – and what you need to do with the material – shape, cut, grind, strip, sand or polish. Angle grinders are not difficult tools to use, but they can result in severe injuries if not used properly. Ensure you understand how to use the tool and its accessory safely.
Price: $40 to $1,000
Power source: 110V (corded), battery, pneumatic
Power output: 12V, 18V, 40V, 60V (battery), 5 to 16.7 amps (corded)
No load speed: 5,000 – 12,000 RPM
Accessory capacity (diameter): 2″ to 9″
Weight: 4 to 13 pounds
If not used properly, an angle grinder can inflict serious damage to your head, face or legs. The most common causes of injury are wheel breakage, kickback and contact with projectiles. Wear all proper PPE when using a grinder.
You’ll get better results and reduce the risk of an accident when using the right accessory. For example, don’t use a cut off wheel for grinding. Not all accessories should be run at the same speed. Check the manufacturer’s recommended speed setting and don’t exceed it.
Don’t assume that you know how to use an angle grinder properly just because you’ve used other power tools. Read the user guide that comes with your angle grinder.
Always position the guard so it deflects debris and sparks away from you. Keep both hands on the grinder when in use so you can control it in the event of kickback and torque reaction. Always secure the item you’re working on.
While you do need to apply some downward pressure when cutting or grinding, there is no need to apply excessive force. This can cause an accessory to break or catch on the workpiece, or it can cause the motor to overheat.