An abrasive wheel that bursts at 3,000 rpm does not give anyone time to react. That is why abrasive wheels are one of the few pieces of workshop equipment where the law is explicit that only a trained, competent person may mount them — and why “he’s used a grinder for years” is not a defence.
At a glance: Nexis CPD offers a £9 CPD-accredited online Abrasive Wheels Awareness course — 100% online and self-paced, with an instantly emailed, employer-verifiable certificate. Any three courses cost £18. It is awareness-level CPD, not a regulated qualification.
This guide covers what the law requires, the hazards that actually cause the injuries, what training must include, and the checks that get skipped.
What the law requires
Abrasive wheels used to have their own dedicated regulations. They no longer do — they are governed by the Provision and Use of Work Equipment Regulations 1998 (PUWER), alongside the general duties in the Health and Safety at Work etc. Act 1974.
The parts that matter:
- PUWER Regulation 9 — training. Everyone who uses work equipment must have adequate training in its use, the risks, and the precautions. For abrasive wheels, mounting is treated as a specific competence.
- PUWER Regulation 11 — dangerous parts. Effective measures to prevent contact with dangerous moving parts. In practice: guards.
- PUWER Regulations 4–6 — suitability, maintenance and inspection of the equipment itself.
- COSHH 2002 for the dust, and the Control of Noise at Work Regulations 2005 and Control of Vibration at Work Regulations 2005 for the other exposures.
Note that no regulation names a certificate, a course length or a renewal period. What is required is competence, evidenced. See how the risk assessment duty works.
The hazards that actually cause harm
Wheel burst
The catastrophic one. A wheel that is damaged, wrongly mounted, run above its maximum speed or unevenly clamped can disintegrate. Fragments leave at the wheel’s rim speed. This is the reason for nearly every rule below.
Contact with the wheel
Abrasion injuries to hands and fingers, and entanglement of gloves, sleeves, jewellery or long hair. Grinding wheels remove skin as readily as steel.
Ejected particles and sparks
Eye injuries are among the most common outcomes. Sparks also create a genuine ignition risk near flammables — a significant proportion of workshop fires start at a grinder.
Dust — including silica
Cutting or grinding concrete, stone, brick or engineered stone releases respirable crystalline silica, which causes silicosis and lung cancer. This is a COSHH matter requiring on-tool extraction or water suppression, not just a dust mask. See COSHH and dust.
Hand-arm vibration
Angle grinders are high-vibration tools. Prolonged use causes hand-arm vibration syndrome — permanent, and one of the most commonly reported occupational diseases. Exposure must be assessed and limited.
Noise
Grinding routinely exceeds the levels at which hearing protection and health surveillance become duties.
What abrasive wheels training must cover
There is no prescribed syllabus, but competent training covers:
- Wheel markings and selection — how to read the specification, and matching the wheel to the material and the machine
- Maximum operating speed — and checking it against the spindle speed of the machine. This is the single most important number on the wheel.
- Storage and handling — wheels stored flat or in racks, dry, away from damp, frost and impact damage
- Inspection before use, including the ring test for vitrified wheels — suspended and tapped lightly, a sound wheel rings; a dull note means a crack and the wheel is scrapped
- Correct mounting — blotters, matched flanges of correct diameter, correct torque, never over-tightening, never forcing a wheel onto a spindle
- Guarding — correct guard in place and positioned so it contains fragments
- Work rest adjustment on pedestal grinders — set as close to the wheel as practicable; guidance commonly specifies a gap of no more than 3 mm, to stop work being dragged in
- Dressing and truing the wheel
- Running-up procedure — stand aside on first start, run briefly before use
- PPE — impact-rated eye protection always; plus hearing, respiratory and hand protection as assessed
- Safe working practice — no side-grinding on wheels not designed for it, no excessive force, secure workpieces
Mounting: the legally distinct bit
Using an angle grinder and mounting the wheel are different competences. Mounting is where the catastrophic failures are designed in — wrong flanges, missing blotter, over-torqued nut, hairline crack missed, speed mismatch.
Employers should be able to say precisely who is authorised to mount wheels and evidence their training. In many workshops that is a smaller list than the list of people who use grinders, and it should be.
The checks that get skipped
- The speed check. Fitting a wheel rated below the machine’s spindle speed. Always compare the two numbers.
- The ring test. Takes seconds; routinely skipped. A dropped wheel that looks fine can be cracked internally.
- Work rest gap. Drifts wider with use and nobody resets it.
- Guard removed “just for this job”. The job it was removed for is the job the guard was for.
- Wheels stored badly. Leaned against a wall, stacked on edge, left damp.
- Expired wheels. Bonded wheels degrade; resin-bonded wheels in particular carry an expiry date that is rarely checked.
- Gloves near a rotating wheel. Sometimes protective, sometimes an entanglement hazard — this needs a deliberate decision from the risk assessment, not habit.
How often should training be refreshed?
No legal interval exists. Common industry practice is every three to five years, and sooner where:
- New equipment or wheel types are introduced
- Monitoring shows unsafe practice
- There has been an incident or near miss
- Someone returns after a long absence from the task
The legal test remains current competence — not a certificate date.
Further reading
Frequently asked questions
Is abrasive wheels training a legal requirement?
Abrasive wheels no longer have their own dedicated regulations — they are governed by PUWER 1998. Regulation 9 requires adequate training for anyone using work equipment, and mounting an abrasive wheel is treated as a specific competence. No regulation names a course, certificate or renewal period; what is required is demonstrated competence, evidenced by the employer.
Who is allowed to mount an abrasive wheel?
Only a trained, competent person. Using a grinder and mounting the wheel are different competences — mounting is where catastrophic failures are designed in through wrong flanges, a missing blotter, an over-torqued nut, a missed crack or a speed mismatch. Employers should be able to name exactly who is authorised to mount wheels and evidence their training.
What is the ring test for abrasive wheels?
A pre-use check for vitrified wheels. The wheel is suspended and tapped lightly — a sound wheel rings clearly, while a dull or dead note indicates a crack and the wheel must be scrapped. It takes seconds and is one of the most commonly skipped checks. A dropped wheel that looks undamaged can be cracked internally.
What is the maximum work rest gap on a pedestal grinder?
The work rest should be set as close to the wheel as practicable, and guidance commonly specifies a gap of no more than 3 mm. The purpose is to stop the workpiece being dragged into the gap between rest and wheel. The gap widens as the wheel wears, so it needs resetting regularly rather than being set once.
What are the main hazards of abrasive wheels?
Wheel burst is the catastrophic one, caused by damage, incorrect mounting, over-speeding or uneven clamping. Others are contact and entanglement injuries, ejected particles and sparks causing eye injuries and fires, respirable crystalline silica from cutting concrete or stone, hand-arm vibration syndrome from prolonged angle grinder use, and noise exposure.
How often should abrasive wheels training be refreshed?
There is no legal interval. Common industry practice is every three to five years, and sooner where new equipment or wheel types are introduced, monitoring shows unsafe practice, there has been an incident or near miss, or someone returns after a long absence from the task. The legal test is current competence, not a certificate date.
Abrasive wheels training
Our Abrasive Wheels Awareness course covers what PUWER requires, wheel selection and markings, storage and inspection including the ring test, mounting, guarding and safe working practice.
Related: COSHH Awareness (for the silica dust) · Noise Awareness · Risk assessment: what UK law requires · COSHH and dust
£9 per course. CPD accredited, 100 % online, verifiable e-certificate on completion. Pay for 2, get 3 — any 3 courses for £18.
Important: this is a CPD-accredited awareness course and general information, not legal advice. It builds underpinning knowledge of the hazards and the legal duties. It is not a practical competence assessment and does not by itself authorise anyone to mount abrasive wheels. PUWER requires demonstrated competence for mounting; that requires hands-on training and assessment on the actual equipment, by a competent person, in your own workplace.