Technical guide · Cutting and grinding discs
Abrasive disc markings explained: how to read a cutting disc label
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A cutting or grinding disc label is the tool’s identity card: dimensions, maximum speed, workpiece material, expiry date and the European standard it was made to.
Using 2026 Tyrolit labels, we explain each marking, how to match the disc to your angle grinder and why a disc without complete markings should never be fitted.
Key takeaways
- Use a disc only if its manufacturer, dimensions, material (at least the bond) and maximum speed are identifiable.
- The grinder’s rated speed must never exceed the disc’s maximum RPM.
- On 2026 Tyrolit cutting and grinding disc labels, the colour shows the workpiece material, not the speed.
- The expiry date (month/year) is usually on the metal ring around the bore; never use the disc after it.
Why disc markings matter
Cutting and grinding discs run at high peripheral speeds. Tyrolit’s safety guidance is explicit: an abrasive may only be used if a minimum set of information can be identified.
Tyrolit labels add the shape and specification, pictograms, the EN standard and the oSa mark. A disc without standard markings tells you neither whether it fits your machine nor whether it is still usable. The mandatory minimum:
- the manufacturer;
- the dimensions of the disc;
- the material, at least the bond type;
- the maximum RPM or the maximum operating speed in m/s.
Dimensions, shape and specification: D × T × H, 41, 42, 27
Dimensions are given as D × T × H, in millimetres and inches: outside diameter, thickness and bore. Example from a Tyrolit label: 125 x 2.0 x 22.23. The bore must fit the spindle exactly, without force.
The number in front of the specification is the shape: 41 is a flat cutting disc, 42 a depressed-centre cutting disc, 27 a depressed-centre grinding disc. Never side-grind with a shape 41 or 42 cutting disc. If you need one disc for both jobs, use one designed for it, such as the Tyrolit CUT AND GRIND (shape 27, 2.0–3.5 mm).
The specification code, for example A 46 N-B F X A, describes the abrasive grain (A = aluminium oxide, C = silicon carbide, ZA = zirconia, CA = ceramic), the grit, the hardness (N = soft … T = hard), the bond (B = synthetic resin) and the glass-fibre reinforcement (F); X is a Tyrolit internal symbol and the final A denotes external reinforcement.
See also: Choosing a cutting disc
Maximum speed: m/s, RPM and matching the grinder
A disc carries two related values: maximum peripheral speed (m/s) and maximum rotational speed (RPM). Tyrolit labels for 125 mm discs read “Max. 12,250/min, Max. 80 m/s”. The same 80 m/s limit means different RPM depending on diameter: according to Tyrolit’s table, 13,200 RPM at 115 mm but only 6,640 RPM at 230 mm.
The practical rule: the rated speed on the grinder’s nameplate must be equal to or lower than the maximum RPM on the disc. Not every disc is rated 80 m/s: some Tyrolit discs for stationary machines are rated 100 m/s, some special discs 50 or 63 m/s.
Never fit a larger disc to a smaller grinder
Small angle grinders run at higher speeds. A 230 mm disc fitted to a 125 mm machine with the guard removed can far exceed its maximum RPM. The Tyrolit label is explicit: “Warning: use a safety guard”.
See also: Abrasive safety
Colour codes: material, not speed
On 2026 Tyrolit cutting and grinding disc labels, the colour shows the workpiece material: blue for steel and for 2in1 discs (steel and stainless steel), red for INOX, orange for non-ferrous metals, violet for cast iron, green for stone.
Speed colour stripes are documented in Tyrolit’s grinding-wheel catalogues: no stripe up to 40 m/s, blue 50, yellow 63, red 80, green 100 m/s. Diamond blades use their own code, again by material (red for concrete, for example).
So red can mean INOX on a cutting disc, 80 m/s on a grinding wheel or concrete on a diamond blade. Colour helps on the shelf; the printed values decide the fitting.
Expiry date, EN standard, oSa and pictograms
On cutting and roughing discs the expiry date is printed as month/year (for example 04/2025), usually on the metal ring around the bore; on other tools it may be on the label. Tyrolit is categorical: never use a disc after its expiry date.
The EN standard shows the safety rules the disc was made to: EN 12413 for bonded abrasives, EN 13743 for flap discs, EN 13236 for diamond blades. Tyrolit is a founding member of oSa, the Organisation for the Safety of Abrasives; according to Tyrolit, the oSa mark guarantees compliance with EN safety standards, regular manufacturing controls and traceability. Common pictograms:
- Goggles, ear protection, dust mask, gloves: the PPE required.
- No side grinding: the disc must not be used on its face.
- Dry or wet cutting/grinding: the working method the disc is designed for.
- Do not use damaged abrasives: a cracked or dropped disc is taken out of service.
- Free of Fe, S, Cl: no iron, sulphur or chlorine, relevant when working stainless steel.
Table: marking, meaning, why it matters
A quick checklist for incoming discs and for every fitting.
| Marking | What it means | Why it matters |
|---|---|---|
| 125 x 2.0 x 22.23 | Diameter × thickness × bore (mm) | The disc must match the machine and the guard |
| Max. 80 m/s, Max. 12,250/min | Maximum peripheral and rotational speed | The grinder’s speed must not exceed them |
| 41, 42, 27 | Disc shape | No side grinding with shapes 41 and 42 |
| A 46 N-B F X A | Grain, grit, hardness, bond | Grain and bond type suited to the job |
| Label colour | Workpiece material | The right disc for steel, INOX, cast iron, stone |
| 04/2025 on the metal ring | Expiry date | After it the disc must not be used |
| EN 12413 | European standard for bonded abrasives | Manufactured to the safety rules |
| oSa | Abrasives safety mark | Regular controls and traceability |
| Manufacturer and address | Who is responsible for the product | No identifiable manufacturer, no use |
Disc with incomplete markings? Do not fit it
If any of the minimum information is missing – manufacturer, dimensions, bond, maximum speed – the disc cannot be matched to the machine and must not be used. The same applies to an illegible label or an expired date.
This is not a formality: a disc that bursts at operating speed can cause serious injury, and the markings are the operator’s only evidence that the disc was designed and tested for the speed it runs at.
Tyrolit disc with EN 12413 and oSa marking, or a disc without standard markings?
A Tyrolit cutting or grinding disc is manufactured to EN 12413 and its label carries the maximum speed, expiry date, pictograms and the oSa mark. Tyrolit’s safety documentation describes a final inspection to EN 12413 that includes dynamic balancing, a burst test, a side-load test and a cutting or grinding test. A disc with no standard markings and no identifiable manufacturer gives you no verifiable information about its maximum permitted speed, its grain and bond type or its usable life. For a tool spinning centimetres from your hands and face, the choice is simple.
See also: Cheap vs premium discs
Frequently asked questions
What does 80 m/s on a cutting disc mean?
The maximum permitted speed of the disc’s edge. The matching RPM depends on diameter: a 125 mm Tyrolit disc is labelled max. 12,250 RPM, which the grinder must not exceed.
Where is the expiry date on a cutting disc?
Usually on the metal ring around the bore, as month/year (for example 04/2025); on cup wheels and other tools it may be on the label.
What does the colour on a cutting disc label mean?
On 2026 Tyrolit discs it shows the workpiece material (for example blue for steel, red for INOX, green for stone), not the speed.
What does EN 12413 on a disc mean?
The European safety standard for bonded abrasives: cutting and grinding discs and grinding wheels. Flap discs fall under EN 13743, diamond blades under EN 13236.
Can I fit a bigger disc than my grinder is designed for?
No. The guard is sized for the machine’s nominal disc diameter and must stay fitted; small grinders also run fast enough to overspeed a larger disc.
Tyrolit discs with complete markings
Galflex is an authorized Tyrolit distributor in Romania. Contact us for help choosing the right disc for your grinder and material.
See the Tyrolit cutting and grinding discs · Contact us for an offer
Sources and documentation
Related guides
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