Portable angle grinders are the most common tools in workshops ,it is also a useful tool for construction work or DIY items at home.However it may also cause dangers and accidents if it is not carefully used by its operators. They are hand-operated and are mainly used for cutting , grinding , finishing , and sanding and so on. They have an abrasive disc like cutting disc or grinding wheel , which is used to cut and grind away the imperfections in work pieces.

Like any other tools, the portable angle grinder also needs to be operated with care due to the risk of hazards associated with it.Injuries and worse case, even deaths were recorded due to the misuse of angle grinders.

Although there are no official record of accidents and injuries caused by angle grinders , the statistics from other countries can still show how dangerous an angle grinder can be. For instance, there were nearly 25,000 injuries while using this tool in United States in 2008. Two years later in Australia, 117 injuries with angle grinders, including 31 serious injuries were recorded and applied for compensation claims. Additionally, a man died due to accidentally cutting his leg with an angle grinder whilst working at home in the United States.

Major Injuries

In spite of being a versatile tool, every year significant numbers of injuries occur from angle grinder due to use of the defective machine, mishandling, use of cutting discs with quality problems, flying rough metal particles, directly contacting the running machine, sudden ejection of machinery parts during operation, negligence about maintaining safety protocols, operation by unskilled operators, etc. revealed by different industrial safety studies and hospital reports across the world. Following is the list of major injuries:

  • Amputation;
  • Laceration;
  • Eye injury and vision loss;
  • Electrocution and burns;
  • Long-term impact injury including permanent damage of organs;
  • Post-injury trauma;
  • Death;
  • Facial lacerations
  • Leg injuries and lacerations due to grinding wheel explosion
  • Amputation of a thumb, thumb tip or finger
  • Disfigurement
  • Penetrating facial injuries
  • Crush injuries

However, keeping in mind of the above causes of injuries, I have designed this article outlining angle grinder safety and several tips to prevent accidents to making operators aware of safety protocols and their strict adherence.

In order to prevent these injuries, you should know more about the causes of the accidents first. For angle grinders. There are three potentially dangerous situations for workers in construction job sites: burst disk, kickback and flying sparks while workers are using them at the construction sites, including burst disk, kickback and flying sparks:

  1. High operational speeds, unguarded and oversized discs on angle grinders can increase the potential for disc bursting. When a disc bursts, fragments can fly outwards and injury the worker and anyone near him;
  2. Whilst cutting or grinder, Angle grinders can kickback when it grabs or jams on the material. Kickbacks will cause the tool to accidentally hitting the worker;
  3. A large amount of sparks is produced while using angle grinders. If there are flammable materials around the working environment, they may catch fire from the flying sparks creating a potential fire hazard.

What should you do next after understanding the causes of the accidents? The next to do is to check and choose the right metal cutting tools for the workers.

Stay tuned for the next articles about tips in choosing the right tools for the right jobs.

Safety risks associated with operation of a cutting disc

There are several risks associated with the use and operation of a grinding wheel. It is therefore important for workers to take certain precautions in order to prevent injuries. Some precautions workers can take in order to avoid injuries include:

  • Wear proper safety devices such as a face shield, protective gloves, and safety glasses
  • Always use a proper guard with the grinding wheel
  • Not overreaching
  • Avoid accidental starting
  • Always stay alert and watch what you are doing
  • Use only manufacturer approved or recommended accessories
  • Do not force the wheel
  • Disconnect the plug from the power source before making any kind of adjustment
  • Secure and support the work piece to a stable platform.
  • Carry out a test run after changing any tool

Hazards Associated with Portable Grinders

  • The abrasive discrotates at very high speeds and can cause serious injuries if you accidentally make contact with it.
  • The cutting and grinding action of the wheel loosens chips and tiny fragments of metal, which could fly into your eyes and cause severe injuries. The sparks produced during the operation could also injure your eyes.
  • In some cases, the wheel itself could disintegrate during the operation, and you could get badly injured by the flying pieces of metal.
  • The sparks produced during the operation could also start a fire, particularly if there are any flammable materials nearby.

Safety Measures to be Followed With Portable Angle Grinders 

It is essential to check the condition of the abrasive disc before mounting it on the machine. If there are cracks or defects, the wheel could easily shatter while rotating at high speeds, which is extremely dangerous for the person to operate it.

One way to find out the condition of the wheel is to do a ring test. You should tap the disc softly using a non-metallic tool and carefully observe the sound produced. If it produces a dull or cracked sound, the disc is most likely defective and not fit to be used. If it produces a clean metallic sound, it is safe to be used.

You should make sure that the wheel is compatible with the machine’s size and fits on the spindle properly. You should tighten the spindle nut so that it can securely hold the wheel in place during the operation. Most importantly, you should make sure the maximum operating speed of the wheel is equal to that of the spindle.

The Necessity of Guards

One of the most effective ways to reduce the operational risks associated with portable grinders is to fit them with guards. The parts that need to be fitted with guards include the spindle nut, the spindle end, and the flange projections. You should also make sure that the guards align properly with the wheel.

Personal Protective Equipment

Wear safety goggles and face shields.

Check if the guards are properly fitted before starting the machine. If they are worn out or damaged, replace them immediately.

Hold the grinder firmly using both your hands during the operation.

Perform repair and maintenance work at regular intervals according to the manufacturer’s specifications.

Operating the Machine Safely

Before you start the portable angle grinder, make sure there is no debris or flammable material nearby, which could be ignited by the sparks produced during the operation.

Make sure the wheel is properly mounted, and the guards are properly fitted.

Turn on the machine and let it run for a full minute to see if the wheel is in proper working condition.

Allow the machine to reach its full operational speed before you start cutting or grinding.

Preventing Portable Grinder Accidents

Portable angle grinder accidents can be avoided for the most part with the help of machine guarding and by following the recommended safety measures. You should be aware of the risks involved and remain alert during the operation so that the element of human error could be avoided to the strongest extent possible.

The cause of the accident is not only due to the operation of the angle grinder, but also the quality of the cutting disc is also very important. Now there is a quality standard for cutting discs, and basically all export manufacturers have European certifications such as MPA . After ensuring the quality of the cutting disc product itself, most of the causes of accidents can be attributed to improper operation and use. Then we have to think about what brand of cutting discs are safer?

Here, we have ultra thin Type 41 cut-off wheel. The size is range from 4inch to 14inch.

These ultra thin Type41 aluminum oxide cut-off wheels are used in an angle grinder to cut metal, stainless steel, and similar materials.

The disc, shown above, has been very lightly used, and has plenty of life left in it. Or at least it had plenty of usable life.

This particular disc expired in 2022. You can see the expiration year stamped on the wheel, on the metal bit towards the center.

Cut-off wheels and grinding wheels should not be used past their expiration dates, and that’s if they’ve been properly stored and handled. Mishandling or storing discs in certain conditions might lead discs to be discarded earlier.

So what happens after cut-off and grinding wheels expire? I can’t speak about performance,because the performance must not be far inferior to the newly produced one , and there is a greater risk of breakage, shattering, or other such catastrophic failure.

I believe that the expiration has more to do about the adhesives used to bind everything together.

Have you ever seen brittle glue failure? Maybe aged rubber bands that broke when stretched?

Many abrasive wheels seem expire 3 years after they’re manufactured. Does that mean that a wheel is guaranteed to fail the very next day, 3 years + 1 day after it’s made? No. Ignoring environmental and handling conditions, a day or two won’t make a difference. But the older a cut-off wheel or abrasive wheel, the greater the chance of catastrophic failure.

UV light, humidity, and temperature fluctuations are some of the favors that could degrade abrasive wheels’ bonding agents over time.

Different types of products might have different expiration times. I have seen bench grinder abrasive wheels with 2 year expiration dates.

ALWAYS wear proper safety gear when using abrasive wheels at any kind. They can and do break, and you need to follow experts’ safety recommendations, such as manufacturers’ .

Abrasive disc should also be inspected before each using. (Are there any other abrasive wheel safety checks that you know of?)

What would happen if I use the expired cut-off wheel, shown above? Chances are that it will perform as well or nearly as well as a brand new disc. But there’s an increased chance that it will fail, at least compared to a newer and non-expired disc used in the same exact manner.

There are enough risks when using cut-off wheels and grinding wheels. I’m not looking to increase those risks in any way, and so I don’t use expired abrasive discs.

Sure, maybe part of the reason for the expiration is to reduce brands’ liability should a 6 year old disc fail and damage something or worse – someone.

But I’m not going to bet my safety, or anyone else’s, guessing as to whether my expired cut-off wheels are safe to use or not. Why take the chance?

I came across the above disc when digging through some storage boxes, looking for personal tools or old samples to give away or donate. There were only a couple of older cut-off and grinding wheels, maybe ten dollar’s worth.

If you use cut-off and grinding wheels often, you probably rotate your supplies, using the oldest non-expired supplies first. If you’re like me and don’t use angle grinders very often, you might have a small stash of wheels.

As always, you should follow manufactures’ guidelines for the safe use of power tool accessories and consumables. When in doubt, seek professional advice or recommendations.

That all said, what have your cut-off and grinding wheel experiences been like? Have you ever been faced with the choice of what to do with an expired wheel?