HSA - Abrasive Wheels

Abrasive Wheels

What is an abrasive wheel?

According to the Regulations, an abrasive wheel can be:

a wheel, cylinder, disc or cone which, whether or not any other material is comprised in it, consists of abrasive particles held together by mineral, metallic or organic bonds, whether natural or artificial,
a mounted wheel or point and a wheel or disc having (in either case) separate segments of abrasive material,
a wheel or disc made (in either case) of metal, wood, cloth, felt, rubber or paper and having any surface consisting wholly or partly of abrasive material, or
a wheel, disc or saw, to any surface of which is attached a rim or segments consisting of diamond abrasive particles,
which is, or is intended to be, power-driven, and is for use in any grinding or cutting operations.

In what places of work do these Regulations apply?
These Regulations apply to the following places where an abrasive wheel is used for any grinding or cutting operation, i.e:

every factory
every other premises to which the provisions of the Factories Act 1955 apply
every dock, wharf, quay, warehouse, line or siding, whereby the provisions of section 86(1) of the Factories Act 1955 applies
every harbour, wet dock or ship, whereby the work being carried out is referred to in section 87(1) of the Factories Act 1955
every place and every line or siding where building operations or works of engineering construction are being undertaken, whereby the provisions of section 88(1) or 89(1) of the Factories Act 1955 apply.

The Regulations state the all practicable steps must be taken to ensure that an abrasive wheel beingused is suitable for the work being carried out, having regard to the risk of injury to personsemployed. What minimum requirements must be met to assist in meeting such steps?

No abrasive wheel shall be used in a machine unless the machine is provided with an efficient device(s) for starting and cutting off the power to the machine and the control(s) of the device(s) shall be in such a position and of such design and construction as to be readily and conveniently operated by the person operating the machine
Where there is a rest for supporting a workpiece at any abrasive wheel, the rest must, at all times while the wheel is in motion, be properly secured and adjusted so as to be as close as practicable to the exposed part of the abrasive wheel, and the rest shall be of substantial construction and properly maintained
A notice regarding the dangers arising from the use of abrasive wheels and the precautions to be observed in relation to them must be affixed in every room in which grinding or cutting by means of abrasive wheels is ordinarily carried out
Where such grinding or cutting is not ordinarily carried out in a particular room, such a notice must be fixed in a place and in such a position that it may be easily read by persons employed in grinding or cutting
The floor of any room where there is a fixed machine on which an abrasive wheel is (or is intended to be) mounted and/or where a portable machine on which an abrasive wheel is mounted is used, must be maintained in good and even condition and, so far as practicable, must be kept clear of loose material and prevented from becoming slippery
No person using an abrasive wheel shall wilfully misuse or remove any guard, or wilfully misuse any protection flanges or other appliances provided, or any rest for a workpiece
Every person employed must make proper use of guards, protection flanges and other appliances, rests for workpieces and, if a person discovers any defect in such appliances or rest, must, as soon as practicable, report it to the occupier, manager or other person in authority.

What other basic safety considerations should be taken into account when working with abrasive wheels?
In addition to the requirements of the Regulations (above), the following may also be considered:

Ensure that only the disc specified for the type of material to be cut is used
Always wear PPE as appropriate
Wear RPE when working on masonry, concrete or other materials that create dust
When starting the machine, ensure that the cutting disc is not in contact with the ground or any other obstruction
Ensure protective guards are in place and in proper working order
When working in confined spaces, ensure there is adequate ventilation
Ensure fire extinguisher(s) and/or water is readily available where working in areas with flammable materials
No person other than the operator should be in close vicinity when an abrasive wheel is in use
Regarding portable machines, the following should also be noted:
Never transport the machine with the engine running
Do not work with the machine above shoulder height
Hold the machine with both hands during use.

Additionally, if generators are used to power any such machines:

Do not refuel with engine running
Do not smoke when refuelling
Do not start/re-start engine where fuel has been spilt
Wipe off any fuel spilt on the tool immediately.

Are there many types of abrasive wheels available?
Various types of abrasives are used in abrasive wheels, as appropriate to the type of work they are designed for. Such abrasive types include:

Regular Aluminium Oxide A, 11A, 12A:
This tough form of aluminium oxide is used for cutting high tensile strength materials, e.g. steel, ferrous metals.
Semi-friable abrasive 48A:
These are suitable for cylindrical, centreless, crankshaft and angle grinding applications.
White Aluminium Oxide WA, 27A, 25A, 77A:
This abrasive is used in precision operations, for grinding hardened or high speed steels.
Special 73A:
This abrasive provides very rapid stock removal in hard materials and gives a very cool cutting action.
Pink abrasive 41A:
This abrasive is another form of highly refined aluminium oxide with a small amount of chromium oxide.
Silicon Carbide C, BC, DC, GC:
These are harder and more brittle than aluminium oxide abrasives, making them particularly suitable for grinding low tensile strength materials, e.g. cast iron, stone, non ferrous metals, non-metallic materials.
Mixed abrasives AC and MA, 51A, 52A:
Different types of abrasives may be mixed to provide a wide range of characteristics.
Superabrasives:
- CBN: These hardwearing abrasives are mostly used in the grinding of tool steel
- D: These Diamond abrasives are mainly used for grinding Tungsten Carbide and for cutting bricks, sharpening tools and precision tips.

What types of issues arise from the use of abrasive wheels?
The types of hazards arising from the use of abrasive wheels include:

Improper selection of wheel
Improper mounting
Over speed
Inadequate guarding
Rotating parts
Flying particles
Source of ignition
Abuse
Negligence
Underfoot conditions
Poor lighting
Imbalance
Improper storage
Dust
Noise

How can I find out what the maximum permissible speed for the abrasive wheel I use at work is?
No abrasive wheel can be operated at a speed in excess of the appropriate maximum permissible speed. Workers can identify the maximum permissible speed:

if an abrasive wheel has a diameter of 55 mm or more, the abrasive wheel itself or its washer must be clearly marked with the maximum permissible speed in revolutions per minute as specified by the manufacturer for that abrasive wheel
if the abrasive wheel has a diameter of 55 mm or less, it cannot be used unless a notice stating clearly the maximum permissible speed in revolutions per minute as specified by the manufacturer for that abrasive wheel is kept permanently fixed in the room in which grinding is carried out
if grinding with an abrasive wheel of a diameter of 55 mm or less is not ordinarily carried out in a particular room, a notice stating clearly the maximum permissible speed in revolutions per minute as specified by the manufacturer must be kept posted at a place and in a position where it may easily be read by persons employed in grinding with the wheel.

How should abrasive wheels be stored?
Correct storage facilities and procedures should be followed in order to ensure wheels are kept undamaged and in sound condition. The following guidelines should be followed:

Suitable racks, bins or drawers should be provided to accommodate different types of wheels used.
The storage room should not be subject to extreme temperature changes, humidity, water or any other liquids.
Organically bonded wheels may be affected by oxidation if stored for long periods. They should not be stored for more than three years after the date of manufacture.
Most plain and tapered wheels should be supported on edge or on a central support.
Thin resinoid, rubber or shellac wheels should be laid flat on a horizontal surface and away from excessive heat to prevent warping
Cylinder wheels and large straight cup wheels may be stacked with corrugated cardboard or similar between them.

Do abrasive wheels have to be tested and inspected?
Yes. Routine inspection and preventive maintenance are essential. Each abrasive wheel must be tested before use in order to ensure it is fit for use. Additionally, a visual inspection should be carried out by a competent person before each use. Any tool in an unsafe or unserviceable condition must be withdrawn from use until defects have been rectified by a competent person.

When is a protective guard needed on abrasive wheels?
A guard must be provided and kept in position at every abrasive wheel in motion except where, because of work being done at a wheel or because of the work ordinarily done or intended to be done at a wheel or because of the nature of the wheel, the use of a guard would be impracticable.

What are the minimum requirements for such protective guards?
Guards must:

so far as is reasonably practicable, be of such a design and so constructed as to contain every part of the abrasive wheel in the event of a fracture of the wheel or part of the wheel occurring while it is in motion
be properly maintained and so secured as to prevent its displacement in the event of any such fracture
enclose the whole of the abrasive wheel, except such part as is necessarily exposed for the purpose of any work being done at the wheel or, where a non-adjustable guard is used, for the purpose of the work which is ordinarily done or ordinarily intended to be done at the wheel.

Is there a HSA approved abrasive wheel training course?
No.

What should be included in this training?
The Regulations state that training in abrasive wheels must include suitable and sufficient instruction in the following matters in relation to each class or type of abrasive wheel in respect of which it is proposed to appoint the person being trained:

proper methods relating to the mounting of abrasive wheels
hazards arising from the use of abrasive wheels and precautions which should be observed
methods of marking abrasive wheels as to type and speed
methods of storing, handling and transporting abrasive wheels
methods of inspecting and testing abrasive wheels to check for damage
the functions of all components used with abrasive wheels, including flanges, washers, bushes and nuts used in mounting, and knowledge of the correct and incorrect methods of assembling all components and of correct balancing of abrasive wheels
the proper method of dressing an abrasive wheel
the adjustment of the rest of an abrasive wheel
the requirements of these Regulations
the use of advisory literature relating to the mounting of abrasive wheels.

Do I need a CSCS ticket to operate an abrasive wheel?
No. CSCS tickets are issued in accordance with training under the Construction Skills Certification Scheme. The Abrasive Wheel Regulations require that any user of abrasive wheels is trained and competent to do so, and so they require formal training in abrasive wheels, but they are not issued with CSCS tickets after such training. This training must be administered by a competent person, in accordance with the Regulations.

Who is allowed mount an abrasive wheel?
The Regulations state that a person can only mount an abrasive wheel if:

They have been trained appropriately, in accordance with the Regulations
They are competent to mount such an abrasive wheel
They have been appointed by the occupier of the place of work to do so.