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A 9 inch (230mm) angle grinder is a serious tool. It cuts more than twice as deep as a 115mm, going through a paving slab, kerb or concrete block in one pass. It also weighs 5 to 8kg and has enough torque to break a wrist if the disc snags.
So the best 9 inch angle grinder is powerful, but it is also the one with the best safety systems: a paddle switch that stops it when you let go, a brake, soft start and kickback sensing. Good handling matters too: a rotating rear handle and anti-vibration side grip make long cuts much easier to control.
If you are specifically cutting or grinding concrete, also read our best angle grinder for concrete guide, which covers blades and silica dust.
At a glance: our top picks
- Best 9 inch angle grinder overall: Makita GA9071X1 Paddle Switch 2,800W 230mm (240v corded) – £269.95 at My Tool Shed
- Best cordless 9 inch: DeWalt DCG460 54v Flexvolt 230mm (2 x 9Ah kit) – £729.95 at My Tool Shed
- Best single-battery 9 inch: Milwaukee M18 FLAG230XPDB Fuel 230mm (bare) – £313.95 at My Tool Shed
- Best budget 9 inch: Einhell AXXIO 36/230 Q Brushless 230mm (2 x 4.0Ah kit) – £238.95 at My Tool Shed
- Best for Makita 18v owners: Makita DGA900 Twin 18v LXT 230mm (bare) – £279.95 at My Tool Shed
- Best Makita 40v 9 inch: Makita GA038G 40v XGT 230mm (bare) – £329.99 at My Tool Shed
How we chose
We compared every 230mm grinder from our UK retail partners and ranked them on:
- Power: 2,000W+ corded or 36v to 54v cordless.
- Safety: paddle switch, brake, soft start and AFT or clutch.
- Handling: rotating handle, anti-vibration grip, weight.
- Real cost: including batteries for cordless models.
The best 9 inch angle grinders to buy in 2026
1. Makita GA9071X1 Paddle Switch 2,800W 230mm (240v corded)
- Disc size230mm
- Power2,800W
- Speed6,600rpm
- SafetyAFT, brake, paddle, soft start
Pros
- 2,800W for less than most cordless 230mm kits
- D-handle rotates for cutting
- Anti-vibration side grip
Cons
- Over 6kg
- Corded
2,800W, a paddle switch, AFT, a brake, soft start and a rotating D-handle, for about £270. Makita's GA9071X1 is the benchmark big grinder, and it is also available in 110v.
2. DeWalt DCG460 54v Flexvolt 230mm (2 x 9Ah kit)
- Disc size230mm
- Power2,800W
- Speed6,000rpm
- In the box2 x 9Ah, charger, case
Pros
- 2,800W: matches big corded grinders
- Wireless tool control for dust extractors
- Brake, clutch and soft start
Cons
- Expensive
- 5.94kg with battery
DeWalt's DCG460 matches the Makita's 2,800W with no cable, and the kit includes two 9Ah Flexvolt batteries. It is the choice for groundworkers who need to cut away from power.
3. Milwaukee M18 FLAG230XPDB Fuel 230mm (bare)
- Disc size230mm
- PowerSingle 18v battery
- Cut depth65mm
- SafetyDisc brake, paddle switch
Pros
- 230mm on one 18v battery
- Fixtec tool-free nut
- Anti-vibration side handle
Cons
- Needs High Output batteries to perform
- Bare tool
One M18 battery instead of two makes the Milwaukee lighter and better balanced. It cuts 65mm deep and has a tool-free Fixtec nut.
4. Einhell AXXIO 36/230 Q Brushless 230mm (2 x 4.0Ah kit)
- Disc size230mm
- Power36v (2 x 18v)
- Cut depth70mm
- In the box2 x 4.0Ah, 2 chargers
Pros
- Cheapest cordless 230mm kit we found
- 70mm depth of cut
- Rotating rear handle, battery spark shield
Cons
- 4.0Ah packs run down fast on 230mm
- No brake
The Einhell AXXIO 36/230 Q kit includes two batteries and two chargers for less than most bare pro tools, and cuts 70mm deep. It suits occasional DIY landscaping.
5. Makita DGA900 Twin 18v LXT 230mm (bare)
- Disc size230mm
- PowerTwin 18v (36v)
- Speed6,000rpm
- SafetyAFT, ADT, brake, soft start
Pros
- Uses two ordinary LXT batteries
- AFT and electric brake
- Battery guard
Cons
- Needs two batteries
- Heavy
If you already have Makita LXT batteries, the DGA900 runs a 230mm disc from two of them, with AFT and a brake.
6. Makita GA038G 40v XGT 230mm (bare)
- Disc size230mm
- Speed6,600rpm
- FeatureAWS dust extractor link
- SafetyAFT, brake, soft start
Pros
- Single 40v battery, no twin packs
- AWS starts your extractor
- AFT and brake
Cons
- 4.6kg to 7.4kg depending on battery
- Bare tool
A single XGT battery, AWS to start your extractor automatically, AFT and a brake. It is the most convenient cordless 230mm for dust control.
Do you really need 230mm?
| Disc | Approx. depth | Weight | Good for |
|---|---|---|---|
| 125mm | 33mm | 2 to 3kg | Most metal and DIY jobs |
| 180mm | 55mm | 3 to 6kg | Heavy grinding, fabrication |
| 230mm | 65 to 70mm | 5 to 8kg | Slabs, kerbs, blocks, thick steel |
If you only cut the odd slab, hiring a petrol cut-off saw or a 230mm grinder may be cheaper. Buy one if you do landscaping, groundwork or heavy fabrication often.
Handling a 9 inch grinder safely
- Always use both handles and stand balanced, never overreaching.
- Support the work on both sides of the cut so it cannot close on the disc.
- Never cut above shoulder height.
- 230mm discs are rated around 6,600rpm, so never fit them to a smaller, faster grinder.
Want the absolute most power? See our most powerful angle grinder guide. Prefer to keep it corded? Our best corded angle grinder guide covers all sizes.
Quick buying checklist
- Do you really need 230mm? Only for slabs, kerbs and thick steel.
- Kickback protection: AFT, KickBack Control or an electronic clutch.
- Brake, soft start and a paddle switch.
- Rotating D-handle for a firm grip in any position.
- 110v on site with a 3.3kVA or larger transformer.
Expert corner: why 230mm grinders are the most dangerous size
A 230mm disc runs at about 6,600rpm, slower than a small grinder, but the bigger disc and motor carry far more torque. When the disc pinches, that torque throws the tool back toward the user. Work safety regulators in Australia report some sites have banned 9 inch grinders for this reason.
Published incident reports include a worker cut from face to chest after a 9 inch grinder kicked back while cutting overhead on a ladder, and an apprentice injured in the groin and leg.
How kickback systems work: Bosch's KickBack Control shuts the motor down in a fraction of a second if a cutting disc jams. With grinding discs, a snag alone will not trigger it. The disc must be forcibly stopped.
Expert tips that save time and money
- Two hands, always, with your body to the side of the cutting line and never behind the disc.
- Never use one above shoulder height or on a ladder.
- Let the disc reach full speed before it touches the work.
- Support both sides of the cut so it cannot close on the disc.
- Consider a 180mm or 125mm. Many jobs do not need 70mm depth. See our concrete guide for when 230mm is worth it.
- Corded or cordless? See our corded guide for transformer sizing.
What owners actually say
These points come from UK trade and hobby forums. We have linked each thread so you can read the full discussion.
- On the MIG Welding Forum, a workshop owner runs a 9 inch grinder fine on a 3kVA transformer, but it trips "after about 3 min's continuous cutting" on a long extension. (MIG Welding Forum: 110v saw on a transformer)
- Farming Forum owners reuse worn 9 inch discs on smaller grinders, but others warn about disc speed ratings. A 230mm disc is only rated for about 6,600rpm. (The Farming Forum: 125mm vs 115mm)
Beginner mistakes to avoid
We see these again and again
- Using a 230mm grinder one-handed or on a ladder.
- Standing directly behind the disc.
- Fitting worn-down 230mm discs to a smaller, faster grinder.
- Buying a 9 inch grinder "just in case" when a 125mm would do.
Read the disc before you fit it
Every resin-bonded cutting or grinding disc sold in the UK carries markings under EN 12413. Two matter most:
- The use-by date is stamped on the metal centre ring as a "V" followed by the date, for example V12/2027. It is set no more than three years after manufacture. Out-of-date resin bonds can break up at speed.
- The maximum rpm must be equal to or higher than your grinder's no-load speed.
A disc's limit is really its rim speed, usually 80 metres per second. That is why bigger discs are rated for lower rpm: 80 m/s works out at about 13,300rpm for a 115mm disc, 12,200rpm for 125mm, 8,500rpm for 180mm and 6,600rpm for 230mm. Never fit a worn-down 230mm disc to a small grinder. It is still only rated for about 6,600rpm, and a 125mm grinder spins nearly twice that fast.
Sources: NT WorkSafe: 9 inch grinder kickback alert · SafeWork SA: angle grinders · Bosch Professional: protection technology · MIG Welding Forum: 110v saw on a transformer · The Farming Forum: 125mm vs 115mm · HSE HSG17: Safety in the use of abrasive wheels · Abrasive wheel marking explained (EN 12413)
Frequently asked questions
What is a 9 inch angle grinder used for?
Deep cuts in concrete, slabs, kerbs, blocks and thick steel, plus heavy grinding. It cuts around 65 to 70mm deep.
Is a 230mm grinder the same as 9 inch?
Yes. 230mm is the metric size of a 9 inch disc.
Can a cordless grinder run a 9 inch disc?
Yes. The DeWalt DCG460, Milwaukee M18 FLAG230, Makita GA038G and Einhell AXXIO 36/230 all do, but they need large batteries.
How heavy is a 9 inch angle grinder?
Typically 5 to 8kg depending on the model and battery.
What is Bosch KickBack Control?
A system that shuts the motor down in a fraction of a second if a cutting disc jams. It is one of the most effective safety features on big grinders.
Why do 230mm grinders spin slower?
Disc rim speed is limited, usually to 80 metres per second. A bigger disc reaches that at lower rpm, about 6,600rpm for 230mm.
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