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125mm grinding disc: what to check before you buy

Updated: 21 October 2026

You already own a 125 mm angle grinder. A 125mm grinding disc for dressing a weld is a depressed-centre wheel about 6 mm thick, used on its face. The bore on a hand-held disc is 22.23 mm. The disc’s maximum speed has to be at least the speed printed on the grinder, and the ring should still be inside its use-by date. This page is that checklist for any pack. The four amazon.co.uk listings we kept are ranked on the [125mm grinding discs](/hub/sanders/125mm-grinding-discs) comparison. Products Compared checked those listings on 19 October 2026. A qualifying purchase can earn a commission at no extra cost to you.

You already own a 125 mm angle grinder. A 125mm grinding disc for dressing a weld is a depressed-centre wheel about 6 mm thick, used on its face. The bore on a hand-held disc is 22.23 mm.

Our top picks

Tyrolit Tyrolit ONE grinding discs (10)

Best overall

Tyrolit Tyrolit ONE grinding discs (10)
4.1/10about £13.32
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Parweld Parweld GS1260 grinding discs (10)

Rank 2

Parweld Parweld GS1260 grinding discs (10)
8.6/10about £11.30
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Tyrolit Tyrolit BASIC 222860 grinding discs (10)

Rank 3

Tyrolit Tyrolit BASIC 222860 grinding discs (10)
6.6/10about £18.00
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On this page
  1. 1.What you are buying
  2. 2.The six checks
  3. 3.How to read the code
  4. 4.What this set does not decide

What you are buying

A grinding disc in this size is a resin-bonded wheel with a depressed centre, shape 27 on a clean specification, about 125 x 6 x 22.23 mm. Tyrolit’s GB page for article 222860 describes 6 mm as the thickness for rough grinding, and it lists that article as form 27, A 30 Q-BF. On the Tyrolit titles in this set, 2-in-1 means steel and stainless. A cutting disc is a different tool. Cutwel puts cutting discs around 1–3 mm and grinding discs around 6–8 mm. If the packet in your hand is about a millimetre thick, stop and read grinding disc vs cutting disc before you fit it. A 125 mm disc belongs on a 125 mm grinder. If the disc stands proud of the guard, you change the disc and leave the guard on.

The six checks

The first check is diameter and guard. The disc and the grinder should both be 125 mm. The second is the bore. Hand-held wheels use 22.23 mm, also written 7/8 inch, which is the bore the oSa marking note for EN 12413 treats as standard. The disc has to slide onto the spindle. Parweld’s title says 22.2 mm and the bullets say 22.23 mm, so you confirm the hole on the disc you unpack. The third check is thickness and job. About 6 mm, on the face, is the grinding wheel. The fourth check is metal and grain. Coarse aluminium oxide in the grit 24–36 band is the stock-removal range Cutwel describes for steel. Parweld prints A24R-BF and says steel. Both Tyrolit titles say steel and stainless. Say iron-free only when the page uses those words. Stainless chemistry is on grinding disc for stainless steel. The fifth check is speed. The disc’s maximum rpm must be at least the grinder’s rated speed. LUKAS lists 12,200 rpm for a 125 mm disc at 80 m/s. Parweld prints 12,200. Merryland’s bullets print 12,250. A figure of 15,300 rpm on some trade tables is the 100 mm row, so do not copy it onto a 125 mm disc. The sixth check is the date and the standard. Resin-bonded wheels for hand-held grinders carry about a three-year use-by date on the ring. EN 12413 is the bonded-abrasive safety standard those markings belong to. A disc past the date goes in the bin.
Tyrolit Tyrolit ONE grinding discs (10)

Testsieger

Tyrolit Tyrolit ONE grinding discs (10)
4.1/10about £13.32
View offer

How to read the code

The useful part of a code such as A24R-BF is the grit number sitting in the stock-removal band. A24 on the Parweld bullets is grit 24. Grit 30, on both Tyrolit listings, is still inside the coarse band Cutwel describes for taking metal off. Neither number is a finish grit. Read the code next to the other fields, because they sometimes disagree. Merryland’s grit-number field says 60, while the material line says A30R-BF. The listing does not explain the difference, so you do not know which figure was packed. Tyrolit ONE’s grit-material field says silicon carbide and another field says steel. Tyrolit BASIC’s amazon listing says aluminium oxide, grit 30, and the GB page’s A 30 Q-BF agrees with a coarse aluminium-oxide wheel. A clean code is still not a stainless certificate. The best 125mm grinding discs page says which of the four packs is for welds, which one names stainless, and which star row describes a different disc.

What this set does not decide

Both Tyrolit raw files leave maximum rpm blank. If the ring is slower than the tool, it does not go on. EN 12413 appears on Parweld, Tyrolit BASIC, and Merryland’s bullets. Tyrolit ONE prints ISO 6344:1991 instead, which is an abrasive-grain standard, not a substitute sentence for the wheel’s maximum speed. Merryland’s 4.6 from 1,074 reviews is a large number on a grinding title, and many of the texts describe cutting. That clash is why this checklist starts with thickness and job, not with stars. None of those rows is a lab ranking, and this URL does not pick a winner.

Common questions

Is 22.2 mm the same bore as 22.23 mm?
22.23 mm is the bore the EN 12413 marking note treats as standard for these hand-held wheels, and sellers also write 7/8 inch. Parweld’s title says 22.2 mm and the bullets say 22.23 mm. The disc has to slide on. Do not open the hole out to make a tight disc fit.
What rpm should a 125 mm disc show?
The disc’s maximum speed must be at least the speed of your grinder. Do not use 15,300 rpm for this diameter. On that same table, 15,300 rpm is the 100 mm row. Both Tyrolit files here omit rpm, so you read the ring.
How long can the disc be stored?
Resin-bonded wheels for hand-held grinders carry about a three-year use-by date. A wheel past that date is finished, even if it looks unused.
Do I need a different disc for stainless?
You need a disc whose own page names stainless. Parweld’s listing says steel and does not name stainless. Both Tyrolit titles say steel and stainless, and they do not print iron-free on the pages we used.
Why does one listing show grit 60 and A30?
Merryland’s grit-number field says 60 and the material line says A30R-BF. Those are different grits, and the listing does not say which one was packed. Until you can read the disc, you do not know which job the wheel will do, so the star rating cannot settle it.

Related pages

How to use 125mm grinding discs

125mm grinding discs

Best 125mm grinding discs: Parweld for mild-steel welds

Grinding disc for stainless steel: what the title says

Grinding disc vs cutting disc on your 125mm grinder

Sources

Sources taken from the research digest. Listings were checked on 19.10.2026.

  1. HSE — PUWER overview (retrieved 19.10.2026)
  2. HSE — Training and competence (retrieved 19.10.2026)
  3. HSE — HSG17 Safety in the use of abrasive wheels (retrieved 19.10.2026)
  4. oSa — EN 12413 marking note (retrieved 19.10.2026)
  5. Tyrolit GB — BASIC 2in1 rough grinding wheels (retrieved 19.10.2026)
  6. LUKAS — speed table via Kammarton (retrieved 19.10.2026)
  7. Cutwel — guide to grinding discs (retrieved 19.10.2026)