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Bosch angle grinder 115 or 125

Updated: October 2026

Choosing a Bosch angle grinder 115 or 125 is not choosing a different thread. Most small Bosch bodies here use M14 spindles and wheels with a 22.23 mm bore, so a larger disc can physically thread on while the guard still expects a smaller diameter. HSE’s HSG17 guidance on abrasive wheels treats the guard as the part that should stop an oversize wheel. The nut matching is the wrong test. This page explains what the extra millimetres buy, which of the ten ASINs state a size, and why one listing still disagrees with itself. The ASIN table is on the [main Bosch angle grinder comparison](/hub/tools/bosch-angle-grinder).

Choosing a Bosch angle grinder 115 or 125 is not choosing a different thread.

Our top picks

Bosch Professional Bosch Professional GWS 18V-8

Best overall

Bosch Professional Bosch Professional GWS 18V-8
9.4/10about £89.44
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Bosch Professional Bosch Professional 18V six-speed body

Alternative

Bosch Professional Bosch Professional 18V six-speed body
9.4/10about £148.99
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Bosch Bosch UniversalGrind 750-115

Best value

Bosch Bosch UniversalGrind 750-115
9.4/10about £44
View offer
On this page
  1. 1.What 115 mm and 125 mm change
  2. 2.Why the nut is the wrong check
  3. 3.What these listings actually state
  4. 4.If you need a deeper cut
  5. 5.Which diameter to plan

What 115 mm and 125 mm change

Screwfix’s UK buying guide frames 115 mm grinders as lighter, for precision and occasional work, with a guide depth around 30 mm. It puts 125 mm tools in the regular small-job camp, near 38 mm. Those are educational figures, not a specification on every Bosch ASIN here. The extra reach is a few millimetres, and the guard must still match the disc. Most titles in this set state 115 mm: GWS 7-115, GWS 9-115 S, UniversalGrind 750-115, both UniversalGrind 18V-75 listings, and 115 mm copy on the about £135.95 blue body. 125 mm enters through the six-speed body at about £148.99. Model 06019N4000 matches Bosch’s UK GWS 18V-11 S page, a 125 mm tool with six speeds from 3,000 to 9,000 rpm. A UK review title also calls it 125 mm, while amazon’s specification table omits diameter.

Why the nut is the wrong check

M14 threads and a 22.23 mm bore let a 125 mm wheel meet a 115 mm guard if you ignore the shroud. HSG17’s buyer-facing point is that spindle speed must not exceed the wheel rating and the guard contains a burst. Removing the guard to make a disc fit defeats both rules. A quick-locking nut on the about £135.95 or £148.99 blue bodies only speeds disc changes. It does not change the diameter the guard encloses. The GWS 18V-8 still uses a spanner nut, and the size rule is the same. The power-off sequence is on how to use a Bosch angle grinder.
Bosch Professional Bosch Professional GWS 18V-8

Testsieger

Bosch Professional Bosch Professional GWS 18V-8
9.4/10about £89.44
View offer

What these listings actually state

Clear 115 mm on the capture: the GWS 7-115 and GWS 9-115 S names, the UniversalGrind 750-115 and 18V-75 titles, and listing copy on the quick-nut 1,100 W body. 125 mm evidence on the six-speed body is a UK review title plus Bosch UK data for order 06019N4000, not a clean amazon specification row. The GWS 18V-8 conflicts: listing copy says 115 mm, one review says 125 mm, and a UK retailer page also says 115 mm. Buy discs for the guard you receive. The PWS 18V-70 scope is only a box. A German review mentions 115 mm, which is not a UK listing statement. The GWX18V-11PS does not state disc size. Do not assume 125 mm from the price. Battery rails are on Bosch blue or green angle grinder.

If you need a deeper cut

None of these ten Bosch listings is a 230 mm grinder. UK guides put paving slabs, thick walls, and repeated deep masonry in a larger disc class, with different weight and kickback. If the job is a thick kerb or site masonry all day, leave this set and compare 230 mm tools, still with the same guard-and-speed rules. Within stated 115 mm, the corded GWS rows and the green UniversalGrind cover light material. Within 125 mm evidence, the six-speed blue body is the dedicated row, if you already own Professional packs.

Which diameter to plan

Plan 115 mm discs and guards when the title or listing copy states 115 mm, and do not upsize because the nut turns. Plan 125 mm on the six-speed body when you are following model 06019N4000 and the UK review title, and still check the guard in the carton because amazon’s table omits the diameter. Leave the GWS 18V-8 unsettled until the box label matches the wheel. There is no 230 mm Bosch in this kept set.

Common questions

Is 125 mm much more capable than 115 mm?
A little more depth and contact area in guide terms, not a different spindle family. Screwfix-style figures put the extra reach near 38 mm of cut depth against about 30 mm, and those are guide numbers, not a Bosch specification row. The guard limit still dominates whichever disc you buy.
Can I fit a 125 mm disc on a 115 mm Bosch if the nut fits?
No safe assumption. The guard rated for 115 mm is the control point. M14 and a 22.23 mm bore can accept the larger wheel while the shroud still expects the smaller one. Oversize wheels are exactly what HSG17-style guidance warns against. Do not remove the guard to make the disc fit.
Which listings here say 115 mm in the title or copy?
GWS 7-115, GWS 9-115 S, UniversalGrind 750-115, both UniversalGrind 18V-75 titles, and 115 mm copy on the about £135.95 blue body. That is the clear 115 mm group on this capture. It does not include the six-speed body or the unsettled GWS 18V-8.
Which listing is the 125 mm one?
The six-speed body at about £148.99, via model 06019N4000 and a UK review title. Bosch’s UK page for that order number specifies a 125 mm tool. Amazon’s specification table omits diameter, so confirm the guard in the carton rather than treating the table as the size.
Why will you not state the GWS 18V-8 size?
Because the capture conflicts. Listing copy says 115 mm, one review says 125 mm, and a UK retailer page also describes 115 mm. Recommending one number would pretend the ASIN is settled. Match discs to the guard and wheel you receive until Bosch or the box label clarifies it.
Do I need a 230 mm Bosch for paving?
Not from this set. There is no 230 mm Bosch here. Paving slabs, thick walls, and repeated deep cuts sit in a larger disc class with different weight and kickback. Plan that comparison separately, and keep the same rule that the guard and the wheel speed must match.
Does a quick nut change the size rule?
No. A quick-locking nut on the about £135.95 or £148.99 blue bodies only changes how fast you swap discs that already match the guard. It does not raise the maximum diameter the shroud encloses, and it does not make an M14 thread a size check.

Related pages

Bosch angle grinder buying guide

Bosch angle grinder

Best Bosch angle grinder: three UK shortlist picks

Bosch blue or green angle grinder: pack compatibility

How to use a Bosch angle grinder for UK first cuts

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.

  1. HSE, HSG17 Safety in the use of abrasive wheels (retrieved 19 October 2026)
  2. HSE, Hand-arm vibration advice to employers (retrieved 19 October 2026)
  3. HSE, CN1 Silica dust (retrieved 19 October 2026)
  4. Electrical Safety First, Angle grinders (retrieved 19 October 2026)
  5. Bosch Professional, AMPShare (retrieved 19 October 2026)
  6. Bosch DIY, POWER FOR ALL (retrieved 19 October 2026)
  7. Bosch Professional, X-LOCK (retrieved 19 October 2026)
  8. Toolstation, Angle grinder buying guide (retrieved 19 October 2026)