On the cutting edge

Abrasive cutting discs are so useful for cutting, grinding and polishing—and using the right ones prevent injuries and cost you far less in the long run. By Rachel Smith

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Last year, a New Zealand-based 16-year-old was working on a mate’s car with an angle grinder, when the cutting disc shattered, sent shrapnel flying into his hands and severing one hand almost to the bone. Luckily, there was no nerve damage—just 36 stitches to sew his hand back together.

It’s one of many stories involving power tools and accidental injuries, which ER departments in Australia see all too often, too. And it’s fair to say those near-misses—from kickbacks or wheels shattering—are something every tradie (and home handyman) fears.

“Thankfully we don’t see it happening a lot, but there have been some pretty gruesome incidences over the years,” says Paul Bertino, Application Engineer at Saint-Gobain Abrasives. “And it’s predominantly because people get complacent and they take shortcuts.”

Not only that—tradies are often choosing cheaper, imported cutting discs which are poorly made, need replacing far more often and are potentially dangerous, adds Paul Hoye, Klingspor Australia’s Managing Director for Asia Pacific.

“We do a lot of testing of these wheels in our training facility, particularly the 1mm wheel because they’re the biggest selling abrasive in Australia,” he says.

“We use a spreadsheet that calculates the cost of the wheel and the hourly rate for the person using it, and the number of cuts—and we can prove without a doubt that using a quality wheel is much cheaper in the long run.”

So how can you use cutting discs cost-effectively, while also staying safe? Here’s how.

It may feel like a no-brainer to grab a box of super-cheap cutting discs off Ebay, or the $1 wheel instead of the $2 option at your local hardware. But there’s a big difference between well-made and badly-made products—and the one you buy should have a symbol for the Organisation for the Safety of Abrasives (oSa)—a globally-recognised safety standard.

All good brands are members of the oSa, a worldwide organisation and being a member means a few things, says Hoye. “Firstly, for every 1000th wheel you make, you have to test to it to make sure it complies, that it runs to a certain speed without breaking. We also do what’s known as a single-point side load test, which puts pressure on the side of the wheel as it spins and we’ll record when the wheel breaks, and whether that’s within tolerance.”

Being a member of oSa means you have to have global product liability insurance, too, which means if a wheel fails (and it’s not due to user error), the user is covered.

QUESTIONS TO ASK BEFORE YOU BUY
If you’re at the hardware store buying a new cutting disc, Hoye recommends asking the following questions before you do:
- “Is it the right disc for what I want to cut?”
- “Does the running speed suits the machine I’m going to use it on?”
- “Does it have a safety standard I’m looking for, like the oSa logo?”

It’s important to ensure tradies are trained to use cutting discs correctly, says Bertino, who’s a Cert 4 Trainer and Assessor.

“At a training session I’ll run through the safety features, explain how our wheels are colour-coded and how to select which wheel for the right job,” he explains. “For example, selecting the correct wheel for cutting or grinding stainless steel and making sure the machine’s speed doesn’t exceed the wheel’s rated speed, because there’s a chance it could explode. I’ll also explain that you should never remove a guard or
handle from the angle grinder, and always wear the correct PPE gear.”

Hoye agrees that many young tradies need more structured training. “They’re given a drill, they’re given a grinder and told, ‘Off you go,’’ he says, “but the good manufacturers have technical reps who can come and do a toolbox talk, explain the do’s and don’ts. We’ve also got safety posters we can give you for free that you can put up in your workplace.”

There are a number of things that can cause issues or injuries when using cutting discs, says Bertino.

“Firstly, using a cut-off wheel for grinding when it’s designed for cutting. Removing guards off machines, as mentioned above. Work pieces not being clamped correctly. Not using the correct grinder or correct wheel for the process,” he says.

Remember these tools can be like a loaded gun and treat them with respect, adds Hoye. “The speed of these wheels are faster than a Formula One racing car—if one breaks and hits you in the face you could be blinded or scarred for life,” he says. “People think because a cutting wheel is a cheap product that it’s not important, but it’s one of the most important things in your toolbox.”

TIPS FOR GOOD WHEEL CARE
Bertino’s tips for wheel maintenance include:
- Check your wheel’s expiry date “Cutting discs have a three-year shelf life, so you should always check the date stamped on the ring before use.”
- Store your wheels correctly “They come in tubs and boxes depending on how you buy them,” says Bertino.
- "They should always be stored flat and dry - never in a damp area.”
- Inspect the machine and wheel before use “Ensure both are undamaged and mounted correctly.”