How to use a Bosch angle grinder
Updated: October 2026
How to use a Bosch angle grinder is a sequence, not a logo choice. The tool spins an abrasive disc fast enough to cut metal or stone and to throw sparks across the room. The guard, the disc rating, and the way you clamp the work cause most injuries, not the model name. This page is the sequence for a first cut or a first disc change on one of the small Bosch tools in the [main Bosch angle grinder comparison](/hub/tools/bosch-angle-grinder). Which ASIN to buy stays on the buying pages.
How to use a Bosch angle grinder is a sequence, not a logo choice. The tool spins an abrasive disc fast enough to cut metal or stone and to throw sparks across the room.
How to use a Bosch angle grinder is a sequence, not a logo choice. The tool spins an abrasive disc fast enough to cut metal or stone and to throw sparks across the room. The guard, the disc rating, and the way you clamp the work cause most injuries, not the model name. This page is the sequence for a first cut or a first disc change on one of the small Bosch tools in the main Bosch angle grinder comparison. Which ASIN to buy stays on the buying pages.
Our top picks
| Badge | Product | Power | Disc change | In the box | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Bosch Professional Bosch Professional GWS 18V-8 | Cordless, 18 V | Locking nut | Guard, no battery | 9.4 | about £89.44 | View offer |
| Best value |  Bosch Bosch UniversalGrind 750-115 | Corded | Not stated | 3 cutting discs | 9.4 | about £44 | View offer |
| Alternative |  Bosch Professional Bosch Professional GWS 7-115 | Corded, 720 W | Locking nut | Guard, no disc | 9.2 | about £67.55 | View offer |
On this page
Before the disc goes on
Start with power isolated. On a corded GWS 7-115 or GWS 9-115 S, pull the plug before you touch the disc or guard. On any 18 V body, remove the battery. If the slide switch on a green UniversalGrind 18V-75 feels stiff, confirm the spindle is still before you mount a wheel.
The disc label must show a maximum rpm at least as high as the tool’s stated no-load speed, 11,000 rpm on the GWS 7-115 for example. Reject cracked wheels and check the use-by date on organic-bonded discs. Match the guard to the diameter. An oversize wheel on an M14 thread is a common trap, and the guard, not the nut, should stop it. Fit the side handle and set the guard before power returns. These corded listings are 230 V or 240 V. Electrical Safety First treats an RCD-protected socket as standard advice for that DIY work. Wear eye and hearing protection, tight clothing, and gloves you can still grip with. Keep sparks away from fuel, solvents, and dry timber.
Fit the disc the way this Bosch allows
The GWS 7-115, the GWS 18V-8, and several other rows use a locking nut and two-hole spanner. The about £135.95 and £148.99 blue bodies list a quick-locking nut. Follow the leaflet for your ASIN: hand-tighten where instructed, and never wedge a disc that does not seat flat on the flange.
On the UniversalGrind 750-115, the scope line names three straight cutting discs. Use them along the edge, not for face grinding. After mounting, reconnect power for a no-load run. Electrical Safety First suggests at least thirty seconds without load so a defective wheel may fail before you engage metal. Keep the guard on during that test.
The cut itself
Clamp the workpiece so it cannot move toward you. Use both hands and the side handle. Let the disc cut with light pressure. Forcing a 720 W corded tool or a small 18 V body builds heat. UK reviewers of the GWS 7-115 mention heat after about ten to fifteen minutes. Stop, let the tool cool, and ask whether the material is too much for a 115 mm machine.
Aim sparks away from people and flammable surfaces. Green cordless reviews note faster battery drain on heavy cuts such as rebar in concrete, so plan spare packs or a mains tool. Concrete raises silica dust risks under HSE CN1. Water suppression, extraction, or a professional belongs in the plan before a patio job. Do not fit chainsaw discs. Electrical Safety First has recalled that attachment class for kickback under UK supply rules.
When you stop
Stop if the disc chips, if the guard cracks, or if vibration appears that you did not feel on the no-load run. Unplug or remove the battery before any disc change. Replace a damaged guard rather than running without it. HSG17 treats the guard as the barrier that contains a burst wheel.
At work under PUWER, wheel mounting may need a trained person. Call a professional for regulated mounting, silica dust without extraction, damaged or out-of-date kit, or a 230 mm job this set does not include. Diameter conflicts are on Bosch angle grinder 115 or 125.
When a professional takes over
A professional takes over for trained wheel mounting at work, for silica-heavy jobs without controls, for damaged kit, and for any cut that needs a larger disc class than these small Bosch bodies. If you are unsure which guard setting matches the wheel type, stop and follow the leaflet rather than removing the shroud to make a disc fit. The buying pages name ASINs. This page assumes you already chose one.
Common questions
Do I unplug before I change the disc?
Yes on corded tools. Pull the plug from the socket before you touch the disc or the guard. On cordless, remove the battery pack before disc or guard work, the same intent as unplugging. Confirm the spindle is still before you fit a wheel, including on a green slide switch that feels stiff.
Which guard stays on for a cut?
Use the guard configuration for cutting or grinding that matches your wheel type and the manufacturer leaflet. Never remove the guard to fit an oversize disc. The nut can accept a wheel the shroud was not built for, and that is the failure the guard is there to prevent.
Can I grind with the cutting disc that came with the £44 tool?
Use the included straight cutting discs on the UniversalGrind 750-115 for edge cutting only, not for face grinding. Buy a grinding wheel rated for your tool if the job is surface grinding. A cutting disc used on its face is a common failure mode across brands.
What should I wear?
Eye protection to BS EN 166 is commonly cited for buyers. Add hearing protection once the disc is running, gloves that still let you grip, and avoid loose clothing. RCD protection at the socket is part of UK DIY guidance for corded 230 V tools. Keep sparks away from fuel, solvents, and dry timber.
Why did the GWS 7-115 get hot?
UK reviews mention heat after extended use, often after about ten to fifteen minutes. Treat that as a cue to pause and cool the tool, not as a measured temperature you should exceed. Forcing a 720 W machine on hard material is a common reason the housing warms up.
Where does a professional take over?
Trained mounting at work under PUWER, silica-heavy jobs without dust controls, damaged kit, and any need for larger 230 mm cutting depth. This kept Bosch set does not include a 230 mm machine. If the guard or disc is cracked, stop rather than finishing the cut.
Are chainsaw discs for angle grinders acceptable in the UK?
No for the recalled attachment class Electrical Safety First warns about. Those products were flagged for kickback and serious injury under UK supply rules. Stick to proper abrasive wheels rated for your spindle speed and guard. Do not turn the grinder into another tool.
Related pages
Sources
Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the ten amazon.co.uk listings captured on 19 October 2026. HSG17 and PUWER apply at work. They are not a certificate for a domestic grinder, and they are not a vibration measurement of these listings.
- HSE, HSG17 Safety in the use of abrasive wheels (retrieved 19 October 2026)
- HSE, Hand-arm vibration advice to employers (retrieved 19 October 2026)
- HSE, CN1 Silica dust (retrieved 19 October 2026)
- Electrical Safety First, Angle grinders (retrieved 19 October 2026)
- Bosch Professional, AMPShare (retrieved 19 October 2026)
- Bosch DIY, POWER FOR ALL (retrieved 19 October 2026)
- Bosch Professional, X-LOCK (retrieved 19 October 2026)
- Toolstation, Angle grinder buying guide (retrieved 19 October 2026)