What Causes Angle Grinder Accidents & How To Prevent?

Angle grinders are powerful handheld tools used on residential areas or construction sites or for cutting, grinding, and polishing. However, using the wrong wheel for the tasks or misusing the device can lead to serious angle grinder accidents.

This article will provide you with some critical statistics on these accidents and the reasons behind them, plus how to prevent these accidents while operating an angle grinder.

How Common Are Angle Grinder Accidents?

Angle grinders are listed in the 3rd position in the top 10 most dangerous tools. According to the statistics collected from 2000 to 2002 by The Royal Society for the Prevention of Accidents (RoSPA), Home and Leisure Accident Surveillance Systems (HASS/LASS), there are approximately 5,400 angle grinder accidents per year.

The most common ones are in the head and face. Besides, there are also limb injuries but less common.

One interesting point, as in the report of the Australian General Engineering, is that the vast majority of these injuries are not in work environments (for example, home use). There are two main groups of people who often suffer from these accidents:

  • Group 1: Those who have just learned to use an angle grinder or have no experience in this hand tool. These people lack safety training, don’t understand the cutting process, or lack safety equipment while doing cutting jobs.
  • Group 2: Those who have been familiar with angle grinders for 15 to 20 years. These people have been confident, so they often use grinders with no safety guard.

Another notable point of these accidents is that most are serious and hard to recover with high disabilities.

What Causes Angle Grinder Injuries?

1. Using higher operational speeds than the manufacturer’s recommendation

The disc rating must be higher than the angle grinder’s rotational speed. Otherwise, you might suffer from injuries.

For example, a grinder with a free rotating speed of 11,000 RPM should be used with a disc rating of over 11,000 RPM.

2. Remove wheel guard

A common mistake of many people is to use an angle grinder without a wheel guard to simplify its operation. You should always use your grinder with the wheel guard to avoid high-speed cutting wheel accidents.

safety glass saved this guy from a broke blade
Safety glass saved this guy from a broke blade – Source: 9gag.com

3. Lack of proper PPE

PPE (Personal Protective Equipment), including safety glasses, gloves, leather apron, face shield, long sleeves and long pants, steel-toe work boots, are mandatory to protect your body when using a powerful hand tool like angle grinders.

When running at high speed, an angle grinder can spread hot sparks, including small metal particles with a temperature up to 3,600oF (2,000oC). If these sparks come into contact with your skin or eyes, they can lead to a facial injury, eye injury, etc.

4. Wearing loose articles, clothing, or long hair

You should avoid wearing fashion accessories (like necklaces closing) or leave your long hair while using an angle grinder. These small and loose objects can get stuck in the grinding disc and result in dangerous accidents.

5. Wrong wheel guard position

Make sure you have correctly installed the wheel guard. Otherwise, you still get caught in hot sparks and metal debris from the grinder.

angle grinder wheel guard

6. Improper body positioning with the grinder and the wheel guard

When running at high speeds, your angle grinder might have unexpected movement and force. An improper body positioning can result in some dangers for you and damages to the tool.

Thus, make sure that you have positioned your body correctly before pressing the “Start” button. Put your feet on a firm and dry surface, and hold the tool with your two hands. Some smaller grinder models allow users to operate tools with one hand.

7. Kickback

Kickback is a common workplace accident, especially for those who use angle grinders. It happens when the tool grabs or jams on the cutting materials, then forcing back towards the operator. This accident leads to severe hand injury or hurts to arms, hands, legs, neck, face, or the groin region.

To avoid kickback injuries, you should choose a suitable angle grinder for the proper cutting task. You should also learn to use this tool properly with safety equipment to avoid unexpected reactions from it, significantly when cutting hard materials or operating at high speeds.

8. Use a damaged cutting wheel

Nothing can be riskier than using a damaged wheel. The friction will grind the material as well as the wheel’s edges. Thus, a wheel that has been used for a long time might experience wear and corrosion.

Ensure that you follow the guideline from the manufacturer and frequently check the wheel’s condition to protect yourself from possible health risks. Additionally, avoid using a wheel that has been torn, damaged, ripped, or has any potential dangers.

a broke disc fly off
a broke disc fly off

9. Reuse big wheels for smaller grinders

There have been many arguments on whether or not you can save your wheel replacement budget by using an old wheel on a big grinder for a smaller one. For example, reuse the wheel on a 7-inch grinder with a 5/8 – 11-inch spindle on a smaller machine until the wheel has reached its lifetime usage.

While it sounds like an excellent way to save your operation cost, this action can lead to bursting risks with high medical costs. Since bigger wheels have lower RPM than smaller wheels, thus, the used wheel from a 7-inch grinder with a rotating speed of 7,000 RPM might not be safe to apply on a 4.5-inch grinder with a rotating speed of 11,000 RPM.

10. Lack of training

Angle grinders are not for experiments. They should be used with high caution. Using a grinder with a lack of knowledge and training can lead to fatal angle grinder accidents.

11. Flying particles

Metal debris and hot sparks from a running angle grinder can fly far from 18 to 21 feet. These flying particles can hurt surrounding people and objects.

12. Hot spark damages

Hot sparks from an angle grinder can damage paint and equipment around it. You should consider this cause, as the repair cost from sparks can be expensive.

angle grinder generates sparks

13. Risks of fire or explosion

You should use EX-certified cold work angle grinders or cutting tools to avoid the explosion risks of hot sparks.

14. Tripping hazard

To avoid slipping or falling when using an electric angle grinder, you should ensure the electrical cable or air supply line doesn’t restrict your mobility and equipment.

15. Shocking hazard

An angle grinder can pose extra threats to its pneumatic parts, like peeling off or cutting its electrical cables. You should stop using the cables as soon as there is any damage. And remember not to use this electric hand tool near a wet area, for example, near water or in the rain.

Safety Tips To Prevent Angle Grinder Accidents

angle grinder safety tips

Wear proper PPE

You should always wear proper PPE when working with this power tool, including leather work gloves, eyes, hearing protection, work apron, natural fiber clothing with long sleeves, and respiratory protection.

Also, never wear loose-fitting clothes, jewelry, or long hair when using this fast-speed cutting tool.

Choose the proper wheel size for your angle grinder

Make sure that you choose the appropriate wheel with your grinder’s disc sizes.

Disc sizes can affect not only the tool’s RPMs but also your safety. An inappropriate disc that is not correctly calibrated for a safe operation will become unstable and kick back toward you if operating at high speed.

Only use a wheel that matches with your grinder’s recommended RPMs

The maximum recommended grinding disc is the safety line you should always follow when using a dangerous cutting tool like angle grinders. This spec is often noted on the tool’s body, in its packaging, or on the product description page.

Never use a wheel that has a lower allowed RPM than the recommended rotating speeds since overdoing will destroy the discs or cause fatal injuries to you.

Always use safety guards as guidance

Safety guards are meant to protect your hands and body from flying particles. They also provide kickback protection when the disc or the wheel breaks or shatters. Thus, always install the safety guards before running your angle grinder, even if you cut a small piece of wood in a few seconds.

The guard positioning is an essential factor you should be aware of when using your grinder with guards. There are some angle grinders with a guard to prevent you from working at risky, awkward angles. If yours doesn’t have that feature, you should find a comfortable position to use the tool rather than removing the guard to make it work faster.

always use safety glass when using angle grinder
Always use safety glass when using angle grinder

Don’t try to customize the grinder

You should ask the manufacturer before making modifications to your grinder. They will help you indicate which modifications are safe and which ones are dangerous to do.

Moreover, only use accessories that are designed for angle grinders. Using the wrong accessories can not only damage the machine but also result in risks to you as well as the people and objects around you.

You can find a list of allowed accessories on the product description or contact the manufacturer for more information.

Examine the abrasives

Always remember to examine the abrasives of the wheel like cracks, chips, or any other damages before working with a brand new or used disc. Why? Cutting wheels can experience drops during shipping or accidentally fell by another person.

Frequent wheel checking helps your machine perform best while keeping you and other people around you safe from wheel damages and shatters.

a crack in angle grinder blade
a crack in angle grinder blade

Warm up the tool

You should freely run the angle grinder with the attached accessory for one minute before using it. This starting step will let the machine warm up to maximize its performance and also a chance to let you check if there is any problem with it.

Keep your working area free of flammable objects

You should make sure there is no flammable object, material, liquids, or gasses in your working area. Otherwise, the flying hot sparks when grinding or cutting metal will ignite fire hazards.

Properly tighten the wheel

Before starting the grinder, you should tighten its wheel using a pin wrench. Don’t use your hand to do this job, because it can be risky.

If you hate doing this job repetitively, you can also choose a Metabo angle grinder with a unique mechanism to tighten or release the discs whenever you want without a wrench.

wrench disc

Control the grinder with two hands

Except for small models with one-hand operation, you should always place your two hands in the correct positions to safely control and maneuver your grinder. Place one hand on the side handle and the remaining one on the back of the tool.

Plus, never place your finger on the “Start” button when carrying the angle grinder, as it can cause accidental starting.


1. Are you allowed to use angle grinder without disc guard?

A disc guard is attached to your angle grinder to protect you from hot sparks or flying metal debris. Therefore, you should never use an angle grinder without a disc guard.

2. Can an angle grinder start a fire?

Cutting metal with an angle grinder causes a lot of sparks. When the sparks fall continuously on a highly-flammable material or object, it can start a fire.

3. Do grinder sparks hurt?

The hot grinder sparks from cutting or grinding metal can hurt you. They have a maximum temperature of 3,600°F (2,000°C) and can burn your eyes, skin or ignite a fire in your work area.

Bottom Line

After knowing common types of angle grinder accidents and how to avoid them, you should bear in mind that there might be other risks that should be noticed. While these risks don’t cause accidents, they can cause serious health issues in the long run.

To maintain the work performance and avoid possible injuries to you and your coworkers, always follow the tool safety cautions. Ask the manufacturer for guidance whenever you are unsure about anything.

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