Working with an angle grinder: risks and measures

on Oct 11, 2026

in Tools & Machinery, Building Materials & DIY

Working with an angle grinder: risks and measures

Cutting, deburring, chasing slots, removing rust: the angle grinder does it all. Precisely because it is so versatile, it is often used for work it was not designed for. A disc spins at a very high peripheral speed. When something goes wrong, it happens fast and the damage is serious. A professional knows the risks, chooses the right disc and works according to fixed habits. That craftsmanship is what makes the difference between a clean cut and an accident.

👷 Working with an angle grinder requires knowledge and experience. If you are new to the trade or work with a large 230-millimetre machine, get instruction from an experienced colleague first. Learning from a professional is never superfluous.

The main risks

Kickback. If the disc jams in the cut, the machine is thrown towards you or upwards with great force. This is one of the most common causes of serious injuries.
Disc breakage. A wrong, damaged or overly old disc can break. The fragments fly off at high speed.
Sparks and fire. Sparks can travel several metres and ignite flammable material, dust or clothing.
Dust. Grinding concrete, stone and tiles produces fine dust containing silica. Inhaling it for a long time can cause permanent lung damage.
Noise and vibration. An angle grinder is very loud and transmits vibration into hands and arms.
Cuts. From contact with the spinning or coasting disc, and from sharp edges on the workpiece.

The right machine and disc

Choose a machine that suits the job. A 125 mm angle grinder is handy for most tasks. A 230 mm angle grinder has more reach, but also more power and a greater risk of kickback; use it only with two hands and plenty of experience. A cordless angle grinder is useful where there is no power supply, but calls for the same care. Always use the disc that matches the material:

A metal cutting disc (125 mm) for steel and a stainless steel cutting disc (125 mm) for stainless steel.
A turbo diamond disc (125 mm) for stony materials such as concrete and tiles. You can read more about drilling and cutting in stone in our blog on diamond drilling in tile and concrete.
A flap disc grit 60 for deburring, weld seams and removing rust.

⚠️ Check that the maximum speed and the diameter on the disc match your machine. Never use a disc that has been dropped, is cracked or has become damp, and never fit a wood saw blade on an angle grinder.

Measures before you start

Check the machine. Is the cable intact, does the switch work properly and is the guard firmly in place? You never remove a guard.
Fit the disc correctly. Always unplug the machine first or remove the battery. Use the correct flange and tighten the clamping nut with the spanner.
Test run. Let the machine run without load for about half a minute, with the disc pointing away from you and nobody nearby. If the disc vibrates or wobbles, stop immediately.
Secure the workpiece. Clamp small and short workpieces with a quick clamp or in a vice. Place long sections stably on trestles or a workbench. Never hold a workpiece between your feet or with your hand close to the disc.
Look at the surroundings. Remove flammable material, watch where the sparks go and put up a screen or barrier if necessary. Make sure there is enough light, for example with a rechargeable LED work lamp.
Arrange hot work. If you work in a building with flammable materials, follow the project rules for hot work, such as a permit, an extinguisher within reach and a follow-up check.

During the work

Always hold the machine with two hands, with the side handle fitted.
Stand firmly and out of the line of the disc. If the disc jams, the machine kicks towards you; your body should not be there.
Let the machine reach full speed before touching the workpiece and do not force it. Do not push sideways with a cutting disc.
Do not work above shoulder height and not on a ladder.
Only put the machine down when the disc has come to a complete stop.
Change discs with the plug pulled out or the battery removed.

Close-up of an angle grinder with a guard grinding a steel box section, a gloved hand steadying the section away from the disc and sparks flying

Personal protective equipment

Eyes and face: always wear impact-protection goggles and, when cutting or deburring, a Univer face shield over them.
Hearing: Thor earmuffs or earplugs are necessary for grinding work. You can read more about choosing hearing protection in our blog on hearing protection.
Breathing: when grinding concrete, stone or tiles, an FFP3 dust mask, preferably combined with extraction via a construction vacuum cleaner suitable for fine dust.
Hands: Comfort Grip leather work gloves protect against sparks and sharp edges. Choose gloves that fit snugly. More about that in our buying guide for work gloves.
Feet and clothing: a safety shoe and close-fitting, flame-retardant workwear without loose parts.

After the work

Let the machine coast to a stop and put it away with the disc facing down or in a safe place.
Check the workplace for smouldering remains, especially if you have worked near wood, insulation material or waste.
Store discs dry and flat so they do not get damaged.
Report damage to the machine or guard and do not use the machine again until it has been checked.

You can find more general rules for working safely on the construction site in our blog on safe working on the construction site.

Frequently asked questions

May I remove the guard if it gets in the way?

No. The guard catches fragments if the disc breaks and directs sparks one way. If you cannot reach the work, choose a different machine or method.

How do I prevent kickback?

Use the right disc, secure the workpiece, hold the machine with two hands, do not force it and make sure the cut does not pinch closed. Stand so that you stay out of the line of the disc.