The Tools we use

Course Content Course Duration - 1hr Hazards and risks arising from use of Abrasive Wheels and the Control Measures. Inspection and Test. Functions of Components - flanges, guards etc. Proper PPE/RPE. Health Risks - Noise Dust Vibration.

This course will give advice on the prevention of accidents when using Abrasive Wheels, in particular:- Injury from breakage Injury from contact Injury from noise Injury from dust & Fume The impact of Noise, Vibration and Dust will also be discussed.

An abrasive wheel is usually defined as a wheel consisting of abrasive particles bonded together using organic or inorganic substances such as resin. 4 4

The Risk of Breakage is inherent in every Abrasive Wheel It is prevented by:- Care exercised in design, in manufacture and testing Safe measures by users. Injury statistics show that nearly half of accidents are due to an unsafe system of work or operator error.

SAFETY - Wheel Breakage Abrasive Wheel Manufacturers carry out tests and inspection to ensure the integrity of their wheels. They will also reinforce wheels. Resin coated glass fibre mats are used in organic wheels to help withstand high stresses and to contain fragments

Bad storage and handling Incorrect selection of wheel SAFETY - Wheel Breakage Breakage may occur in service due to:- Bad storage and handling Incorrect selection of wheel Improper mounting Excessive imbalance Excessive speed Grinding machine defects Malpractice Two or more factors may act together.

Examination of Wheels Visual check Check classification for suitability Ensure suitability for grinder - depressed centre or flat? Ensure suitability for task grinding or cutting? If in doubt consult Supervisor

Safety and PPE

HAZARDS Noise Dust and Fume Vibration Contact with Wheel Wheel Breaking Risk to others

Noise Depends on workplace Depends on material Grinders Always Above 70db Use protection Think of others in area Manage PPE

Dust and Fume depends on environment depends on material paint removal chemicals, temperature wear PPE/RPE

use low vibration tools keep hands warm don’t grip too hard maintain circulation report problems do not apply excessive pressure

Contact with Wheel & Job plan the job get in a good balanced position don’t over reach or stretch don’t use unsuitable access

Wheel Breaking Chose, right wheel for the task. don’t bend or stress wheel. ensure disc is compatible with grinder. ensure disc is correctly fitted. wear correct PPE for the task

Risk to others plan the job consider barriers use sheeting or tents if possible

SPINDLE SPEED Peripheral speed on a fixed speed spindle will decrease as diameter of wheel shrinks. Tendency to use more force - may cause breakage, Change disc before it gets to low. SPEED REDUCES TEND TO USE MORE PRESSURE

Stresses on an Abrasive Wheel are greater nearer the hole. FLANGES Stresses on an Abrasive Wheel are greater nearer the hole. Hence flanges are fitted. Flanges should be at least one third diameter of wheel. Therefore if unreasonable side force is applied disc may break Or disintegrate near centre. STRESS INCREASES

Reinforced resin bonded wheels Cutting or Grinding Flat or depressed centre Up to 230mm diameter Portable Machines May have smaller flanges G Type 41 Type 42

Securing the Wheel Fit freely but not loosely - if tight, spindle could expand and crack wheel. Central nut fixing - only tight enough to prevent wheel slipping After mounting check speed marked on wheel or blotter is not exceeded by that marked on spindle. WHEEL KEYS

Summary of Wheel Mounting Procedures Trained Person Compatible Machine Inspect for damage Flanges correct for wheel Wheels and flanges free from foreign matter

GUARDS - three main functions To contain wheel if it bursts 2. To prevent operator coming in contact with wheel. 3. Also protects wheel from damage and prevents fitting of oversize wheel.

Guards - for portable machines Enclosure 1750 Front Lip 5mm

PORTABLE AND HAND HELD GRINDING MACHINES

Only organic bonded wheels to be used. PORTABLE AND HAND HELD GRINDERS Only organic bonded wheels to be used. Cutting wheels should have fibreglass reinforcement. Machine guards must be securely in place Guard between user and rotating wheel. Serious often fatal incidents, when guard removed to allow larger wheel to be fitted.

ELECTRIC GRINDERS Damaged cables are not to repaired under any circumstances Plug and sockets compatible Regular Inspections by competent electrician Do not try to repair, return to stores Always inspect daily before use

MZ12A768 CHOP SAW - maximum peripheral speed REINFORCED ORGANIC ACME MZ12A768 Type 41 REINFORCED ORGANIC BOND - 100 m/s

SUMMARY OF PRECAUTIONS Training Housekeeping Mounting of Wheels Speed Guards Rests Lubrication New Wheels Stopping Wheels Overhang on Mounted Wheels

Thank you