Abrasive Wheels Training

OBR Construction — Mandatory Health & Safety Module

~25 minDuration

10Questions

75%Pass Mark

12 MonthsCertificate Validity

Your Full Name

This name will appear on your completion certificate. Please enter it exactly as you would like it to appear.

! Why This Training Matters

Abrasive wheels — including angle grinder discs, cutting discs, and grinding wheels — are among the most dangerous tools used on construction sites. Every year in the UK, abrasive wheel accidents cause serious injuries including amputations, lacerations, eye injuries, and fatalities.

This training covers the Provision and Use of Work Equipment Regulations 1998 (PUWER) and HSE guidance on the safe mounting, use, and storage of abrasive wheels. Only trained and competent persons are permitted to mount abrasive wheels.

⚠️ Legal Requirement: The Abrasive Wheels Regulations 1970 (now incorporated into PUWER 1998) require that abrasive wheels are only mounted by people who have received adequate training. This course satisfies that awareness requirement.

1 Types of Abrasive Wheels & Their Hazards

Abrasive wheels are used across construction for cutting, grinding, and finishing work. Understanding the different types and their specific hazards is the first step to working safely.

⚙️ Angle Grinder Discs

Used for cutting and grinding metal, concrete, and masonry. Operate at very high speeds (up to 11,000 RPM). Most common cause of abrasive wheel injuries on construction sites.

🔵 Cutting Discs

Thin discs designed for cutting only — never for grinding or side pressure. Using a cutting disc for grinding is a leading cause of disc bursting. Always check the disc type before use.

🟤 Grinding Wheels

Thicker wheels designed for grinding and material removal. Must not be used for cutting. Bench grinders and pedestal grinders use fixed grinding wheels that must be correctly dressed and guarded.

💎 Diamond Blades

Used for cutting concrete, tiles, and masonry. Generate significant dust including silica dust — respiratory protection is always required. Must be used with water suppression where possible.

Key hazards associated with abrasive wheels:

Bursting — a wheel spinning at high speed can shatter, sending fragments at lethal velocity
Contact — direct contact with the rotating wheel causes severe lacerations
Ejected material — sparks, swarf, and debris at high velocity
Dust — fine particles including respirable crystalline silica (RCS) cause lung disease
Noise and vibration — prolonged use causes hearing damage and HAVS
Fire — sparks can ignite flammable materials in the area

2 Legal Requirements

The use of abrasive wheels is governed by several pieces of legislation working together:

Provision and Use of Work Equipment Regulations 1998 (PUWER) — requires equipment to be suitable, maintained, and only used by trained people. The original Abrasive Wheels Regulations 1970 are now absorbed into PUWER.
Personal Protective Equipment at Work Regulations 1992 — requires appropriate PPE to be provided and worn
Control of Substances Hazardous to Health Regulations 2002 (COSHH) — covers dust generated during cutting and grinding
Control of Noise at Work Regulations 2005 — applies to noise generated by angle grinders and cutting equipment
Control of Vibration at Work Regulations 2005 — applies to hand-arm vibration from grinders

📋 Key PUWER Requirements for Abrasive Wheels:

Only trained and competent persons may mount abrasive wheels
Equipment must be maintained in good repair and inspected regularly
Guards must be fitted and correctly adjusted at all times
Maximum operating speed of the wheel must never be exceeded
Suitable PPE must be provided and worn

❌ It is illegal for an untrained person to mount (fit) an abrasive wheel. This is one of the most frequently prosecuted offences under PUWER on construction sites.

3 Pre-Use Checks — Before You Start

Every time you use an abrasive wheel, you must carry out checks before starting work. Never skip these steps — a defective wheel or incorrect setup can be fatal.

Check the wheel:

Inspect for cracks, chips, or damage — never use a damaged wheel
Perform the ring test — tap the wheel gently with a non-metallic object. A clear ring indicates it is sound; a dull thud indicates a crack
Check the maximum operating speed (RPM) marked on the wheel — it must be equal to or greater than the machine speed
Check the wheel is the correct type for the job — cutting discs for cutting, grinding wheels for grinding
Check the expiry date — abrasive wheels have a shelf life and degrade over time

Check the machine:

Guard must be correctly fitted and adjusted to the minimum gap
Flanges must be clean, undamaged, and the correct size
Check the spindle speed matches or is below the wheel's rated speed
Power cable and switch must be in good condition
Ensure the work area is clear of flammable materials and other workers

❌ Never use a wheel that:

Has been dropped — internal damage may not be visible
Has been stored in damp conditions or exposed to freezing temperatures
Has an RPM rating lower than the machine speed
Is cracked, chipped, or has an uneven face
Has passed its expiry date

4 Mounting an Abrasive Wheel

Only trained and competent persons may mount abrasive wheels. The mounting process must be followed correctly every time — incorrect mounting is a primary cause of wheel bursting.

Disconnect the power — always disconnect from the power source before changing a wheel
Remove the old wheel — use the correct spanner. Never use makeshift tools. Note: the locking nut on angle grinders is usually left-hand thread
Inspect the flanges — clean and check for damage. Flanges must be the correct size (at least 1/3 the diameter of the wheel)
Check the new wheel — ring test, check RPM rating, check expiry, inspect for damage
Fit the blotter/paper washers — these compress slightly to distribute clamping load evenly. Never omit them
Fit the wheel — the wheel should be a free fit on the spindle, not forced. Do not use adaptors to make an ill-fitting wheel fit
Tighten the nut — hand-tight then a quarter turn with the spanner. Do not overtighten — this can crack the wheel
Refit the guard — ensure it is correctly positioned before reconnecting power
Test run — run the machine at full speed for at least 60 seconds in a safe direction before use

⚠️ Stand to the side during the test run — never stand directly in line with the wheel in case it bursts.

5 Safe Working Practices & PPE

Even with a correctly mounted, undamaged wheel, safe working technique is essential. Most angle grinder injuries happen during use, not during mounting.

During use:

Always keep the guard in place and correctly positioned — never remove it
Use both hands on the grinder at all times
Never apply excessive side pressure to a cutting disc
Let the wheel do the work — do not force it
Never use a cutting disc for grinding or vice versa
Keep other workers and members of the public out of the work zone
Be aware of where sparks are going — check for flammable materials
Never put the grinder down until the wheel has completely stopped
Do not use a grinder near flammable liquids, gases, or dusts

⛑️ Minimum PPE Required

Face shield (not just safety glasses)
Safety glasses beneath the face shield
Leather or cut-resistant gloves
Hearing protection
Dust mask (minimum FFP2 for masonry/concrete cutting)
Steel toe-capped boots
No loose clothing or jewellery

🌬️ Dust Control

When cutting concrete, stone, or masonry — use wet cutting methods or local exhaust ventilation (LEV) wherever possible. Silica dust causes silicosis, an irreversible and fatal lung disease. An FFP3 mask is required if dust suppression is not possible.

🔇 Noise & Vibration: Angle grinders typically exceed 85dB — hearing protection is mandatory. Limit continuous use to manage HAVS exposure. Record daily vibration exposure using your OBR HAVS app.

6 Key Summary — What You Must Remember

✅ DO

Always inspect the wheel before use
Perform the ring test on every wheel
Check the RPM rating matches or exceeds the machine
Keep the guard fitted and adjusted
Wear full PPE including face shield
Disconnect power before changing wheels
Stand to the side during the test run
Use dust suppression when cutting masonry

❌ DON'T

Mount a wheel without training
Use a cracked, chipped, or dropped wheel
Remove or bypass the guard
Use a cutting disc for grinding
Apply side pressure to a cutting disc
Exceed the wheel's rated RPM
Put the grinder down while the wheel is still spinning
Work near flammable materials without checking

🔁 Certificate Validity: This Abrasive Wheels certificate is valid for 12 months from the date of issue. Annual refresher training is required.

? Knowledge Assessment

Answer all 10 questions. You must score 75% or above (8/10) to pass and receive your certificate.

Question 1 of 10

Who is legally permitted to mount (fit) an abrasive wheel?

Any worker on site Only the site manager Only trained and competent persons Any worker who has used a grinder before

Question 2 of 10

What is the purpose of the "ring test" on an abrasive wheel?

To check the wheel's RPM rating To check for cracks — a clear ring indicates the wheel is sound To check the wheel fits the spindle correctly To check the wheel is the correct diameter

Question 3 of 10

The maximum operating speed (RPM) marked on a wheel must be:

Lower than the machine speed to allow for safety margin Exactly the same as the machine speed Equal to or greater than the machine speed The RPM rating is not important for safety

Question 4 of 10

You drop an abrasive wheel onto a hard floor. The wheel appears undamaged visually. What should you do?

Use it — if it looks undamaged it is safe Perform a ring test and if it rings clearly, use it Do not use it — a dropped wheel may have internal damage that is not visible Ask a supervisor to inspect it visually before use

Question 5 of 10

When should you disconnect the power supply from an angle grinder?

Only when storing it overnight Before changing the wheel and before any maintenance Only when the machine develops a fault It is not necessary to disconnect power when changing wheels

Question 6 of 10

Which of the following is correct regarding cutting discs?

Cutting discs can be used for grinding as they are stronger than grinding wheels Cutting discs are designed for cutting only and must never be used for grinding or with side pressure Cutting discs and grinding wheels are interchangeable Side pressure is acceptable on cutting discs for small adjustments

Question 7 of 10

What minimum PPE should always be worn when using an angle grinder?

Safety glasses only Safety glasses and gloves Face shield, safety glasses, gloves, hearing protection, and dust mask Hard hat and hi-vis only

Question 8 of 10

After fitting a new abrasive wheel, what should you do before starting work?

Start work immediately — the pre-use checks are sufficient Run the machine at full speed for at least 60 seconds standing to the side, before use Ask a colleague to watch while you start cutting Run at half speed for 30 seconds then full speed

Question 9 of 10

When cutting concrete or masonry, which dust hazard requires specific respiratory protection?

Carbon monoxide Asbestos fibres Respirable crystalline silica (RCS) Nitrogen dioxide

Question 10 of 10

The guard on an angle grinder must be:

Removed when cutting to allow better visibility of the work Fitted and correctly adjusted at all times during use Optional — it is the operator's choice whether to use it Only required when cutting metal

Certificate of Completion

Abrasive Wheels

This is to certify that

Abrasive Wheels Awareness Training

Has successfully completed the OBR Construction Abrasive Wheels online training module in accordance with the Provision and Use of Work Equipment Regulations 1998 (PUWER) and HSE guidance on the safe use of abrasive wheels in construction.

Score Achieved

Date of Issue

Valid Until

Trainer

Martin Jones

Reference

📤 Recording your completion...