Why We Hate a Dangerous Cutting Disc
A cutting disc spins faster than a race car tyre, and it is no joke when one ‘fails’ at high speeds. By ‘fail’, of course, we’re referring to the process whereby chunks of a material hard enough to cut steel ranging in size from a beer mat to a grain of rice fly into the air spinning like ninja stars. God help you if you took off the safety shield.
So, what are the worst things that can happen if you use a cheap cutting disc, or even use a good one the wrong way?
The cutting disc can break apart in use
A cutting disc is always in danger of breaking. Just think about the amazing centrifugal force the edges of that cutting disc experience at high RPMs. When they do fail when spinning at high speeds, they can cause horrible injuries.
How can you prevent cutting disc explosions? To start with, buy higher quality cutting discs. Next, throw a disc away if it is too old, if it is damaged at all, if it is uneven at all or if you know it has been stored incorrectly. Next, check the cutting disc’s rating, and do not use it in a grinder or other tool which can spin at a rate higher than this. Finally, use discs designed for exactly the tool you are using. Never ‘bodge it’ or improvise a way to fit the wring disc to your grinder.
The grinder can ‘kick back’
When an angle grinder mounted with a cutting disc ‘grabs’ or ‘jams’ in the material you’re trying to cut, all of that spinning force gets translated to kinetic energy. This might mean the piece you are cutting getting thrown violently across the shop, but more likely it will mean the entire grinder lunging forward and away from you or – much worse – back up and right at your face.
You can reduce the risk of kickback by using a high-quality cutting disc, making sure the disc is rated to cut the material you are using it on, and that you have the grinder set at the right speed. Finally, change cutting discs often. A dulled cut-off wheel is much more likely to kick back than a fresh one.
Your clothing can get caught up in the grinder
We’ve all heard of accidents where someone’s sleeve or tie gets caught up in an industrial machine, and they are torn to pieces – or at least we remember that scene in the second Indiana Jones movie.
You won’t get your entire torso smashed inside an angle grinder, but there is plenty of force there to take off a few fingers or rip the flesh from your forearm.
First off, don’t wear loose dangly stuff around power equipment. Or 1920s rock crushers. But second off, don’t use cheap cutting discs. A poor-quality disc is more likely to develop a chipped or uneven edge, which will in turn be more likely to snag on clothing and lead to a horrible accident. A good, new cutting disc is more likely to slice a neat hole in your sleeve – not good, but not anywhere near as bad.