Brandon Hire Abrasive Wheels Training Guidance on the regulations and handling of abrasive wheels. The correct selection and fitting to portable and fixed machines

Hello / Introductions Distractions / Resources Why are we here? BSI Labelling system Identification & Selection of wheels Handling, storing & transporting abrasive wheels Mounting wheels Dressing & Truing Legal requirement for tools rests Review / Assessment Welcome & Order of Play

Lets Get Started Distractions – phones off, radio’s, loud people and machinery at a distance Resources – We will need: –A space / desk area for writing –A selection of abrasive wheels –A selection of grinders –Lunch / break arrangements / times agreed Session Risk assessment – to complete together (PPE)

Why are we here? The course helps fulfil employers' responsibility to provide instruction in the use of Abrasive Wheels and associated equipment, as required by the "Provision and Use of Work Equipment Regulations 1998" and "Personal Protective Equipment at Work Regulations 1992". To provide information and practical instruction to enable the delegates to comply with the requirements of the relevant legislation relating to the safe use of abrasive wheels. The safety of yourself, colleagues and members of the public

Why Training? The provision of suitable training is fundamental to the requirement of the Health and Safety at work Act These regulations re-affirm the requirement to provide adequate and sufficient knowledge and training employees and supervisors alike.

Abrasive Wheels Regulations 1970 Implemented in 1970 due to the amount of accidents and incidents involving abrasive wheels and discs No longer used (Poster) Superseded by PUWER 93 and PUWER 98 Still used as ‘common practice’

Regulation 9 – Training Employees & Employers have responsibilities – Team effort Employers – Must provide training, resources, risk assess, manage, guide and supervise employees who use work equipment. This must include correct methods and techniques as well as any precautions to take when using them Employees – Must attend training and apply what they have learned. They must also report any hazards or reasons why they can’t follow the procedures to their manager Provision & Use of Work Equipment Regulations 1998

HSG17 Safety in the Use of Abrasive Wheels Advisory literature Hazards arising from use Methods of marking as to size and type Testing and inspecting wheels Function of components & method of mounting and balancing wheels Methods of dressing a wheel The adjustment of the rest The selection and use of Personal Protective Equipment

Machine types using Abrasive Wheels in the Hire industry Angle grinders Bench grinders (off-hand grinders) Chop saws Clipper saw Petrol cut off saws (Stihl saw) Provision and Use of Work Equipment Regulations 1998

Angle Grinders

Bench Grinder

Bench Saws

Chop Saws jcs: Chop saw jcs: Chop saw

Petrol Cut off Saws

Floor Saws for cutting concrete

Causes of Accidents Eight Most Common Causes of Accidents (not in order) Not using any or suitable eye protection Using wrong disc or wheel Vibration and/or excessive speed Using a cold wheel or disc Failing to hold the work piece correctly Improper use of tool rest Grinding below the wheel centre Not using blotters/wrong flanges

CAUSES OF ACCIDENTS Contact injuries60% Eye injuries30% Burst wheels10%

Any Questions So Far

Definition - Abrasive wheel. A grinding tool consisting of bonded abrasive grains. Includes diamond and reinforced wheels. The Abrasive The Bond Reinforcement Baked Common cause of a disk breaking is overheating and the breaking down of the bonding.

Types Of Abrasive Wheels How many different types of abrasive wheels are there in regular, daily use?

Types of Abrasive Wheels Type 1 – Straight sided vitrified wheels for bench grinders Type 27 – Depressed centre grinding wheels Type 41 – Straight sided cut off wheels Type 42 – Depressed centre cut off wheels Diamond Blades

Type 1 – Straight sided vitrified wheels for bench grinders

Type 27 – Depressed centre grinding wheels

Type 41 – Straight sided cut off wheels

Type 42 – Depressed centre cut off wheels

Diamond Blades

Types of Abrasive Wheels

Abrasive Wheel Markings What information or markings do you think must or should be on a wheel or disk?

Wheel Markings Wheels must have the speed clearly marked in RPM Other information should include Sizes:- Diameter, Bore & Thickness Suppliers name:- Accountability Usage:- Stone or metal (steel) BS marking Expiry date

Wheel Markings

Abrasive Grit BS Markings System 2 Basic types of abrasive grit Aluminium Oxide = A Used on tensile materials Silicone Carbide = C For use on non-tensile materials (brick, stone etc) Note there are variants on the above.

Abrasive Grit BS Markings System Grit size indicated next – rated as 24 – 100 The lower the number, the more coarse the grit Represents the number of holes in a sieve per linear inch Sometimes now, is expressed in microns.

Abrasive Grit BS Markings System Wheel hardness follows on, shown as letters A – Z Where A is the softest And Z is the hardest

Abrasive Grit BS Markings System Bond is shown next as either V for Vitrified Or B for Bakelite (aka Resinoid) (occasionally there may be other bonding, e.g R is for rubber or E is for shellac)

Abrasive Grit BS Markings System The final letter will indicate whether or not any reinforcement is present: indicated as F The reinforcement is (generally) fibre glass, and is not present in vitrified wheels. Very occasionally the manufacturers will add other letters for their own coding.

BS Markings System Typical BS AAluminium Oxide 36Medium Grit PMedium Hardness BBakelite (Resinoid) FReinforced

Dimensions Cutting off disc Maximum 4mm thick Up to 450mm diameter (18”) (Rarely used over 300mm or 350mm) Grinding disc Minimum 5mm thickness Maximum diameter 230mm

Any Questions So Far?

How should an abrasive wheel be? Handled Stored Transported

Handling an Abrasive Wheel Handle with care Use mechanical aids for larger wheels Wear the necessary PPE Do not drop Do not roll Do not tread on the wheel Do no obliterate the markings

Storing Abrasive Wheels Dry – Dust free environment Avoid extremes of temperature Upright where possible Segregated Off the floor – in racking or on pegs In manufacturers packaging By date order (shelf life?)

Transporting Abrasive Wheels Contained (not to move about) Secure Similar rules to handling Be careful with sale or return discs! *Remember – the wheel should never be transported on the grinder*

Methods of Testing How would you test a Resinoid Wheel?

Methods of Testing Resinoid Distortion Cracks and chips Contamination (Oil, Chemicals, Water) BSI Marking

Methods of Testing How would you test a Vitrified Wheel?

Methods of Testing Vitrified All previously listed plus THE RING TEST Suspend on a non-metallic object Tap wheels at 8 points Listen for a clear ring - Difference between a bell and a lump of metal Dull wheel – damaged wheel

Other Components Blotters – Can be self adhesive, Spread the clamping force evenly. Required on all vitrified wheels and cut-off wheels over 400mm(14”). Flanges – Fix the wheel to the machine and provide the drive or rotation. Must be Equal size Undamaged – Burrs, high spots, rounded edges when grinding, (TS400) Correct for the machine Dish Flanges – Larger to support more of the disc. Vitrified and over 9”

Personal Protective Equipment Hard Hat (if working on site) Hearing Protection Goggles (Examples - must be BS2092 grade 1 impact or EN166-B) Mask-respirator (Kidney stones, lung problems) Fire retardant overalls Gloves suitable and correct fitting Safety footwear

Mounting of Discs Correct size including bore, RPM, application Inspect the Equipment, safety devices fitted by manufacturers must be maintained Flanges Check for damage Correct way around - Which way should a disk be mounted? Do not over tighten Wait for machine to reach operating speed – 80% wheel failures are in the first 30 seconds

Mounting Wheels- Practical Fit Wheels to machines!

Cutting and grinding with abrasive wheels Where is the work surface on the example wheels? Cutting – Straight Grinding – 30 degree angle to work surface Don’t forget it is essentially particles and glue Once abrasive is spent it breaks off to reveal fresh abrasive Beware of undermining the disc Only 1/3 of a disk to be used

Wheel Balancing Necessary if balance weights are fitted Unbalanced wheel will cause vibration Can also cause chatter marks on job Possible wheel burst

Adjustment of the Tool Rest The tool rest must be fitted Adjust to no more than 2mm (maximum) from the wheel Must be on or above the centre line of the wheel itself

Truing and Dressing Abrasive wheels For precision Grinding,it is essential that the cutting surface of the grinding wheel is kept in good condition to maintained a safe,effective and economical process The methods used are TRUING and DRESSING and although carried out in a similar manner,are quite individual.

Truing. The shaping process will ensure the wheel is running concentrically with the spindle rotation. Will help avoid work piece ‘skipping’ or jumping Should be done regularly Carried out on off hand grinders

Dressing The removal of worn out abrasive particles from the wheels face. Signs that the wheel needs dressing: bad surface finish with lines or burn marks on the work piece. Wheel may appear shinny and clogged. Uncovers fresh grit Squares up the face Removes foreign matter Requires full PPE

Hand Arm Vibration Identification (Vibration Safety Guide) Stickers (HAE coloured) Safety Sheets (HAE 2150)

10 questions 10 questions No pass / fail Thanks for your time Feedback Review