Abrasive Wheels Training Certificate Work Rest Adjustment and Operating Techniques 3

Question 1

What is the maximum recommended gap between the spark arrestor (tongue guard) and the abrasive wheel?

Accepted Answer

6 mm

Answer

The spark arrestor or tongue guard must be adjusted to within 6 mm of the wheel to limit the exposed arc of wheel and deflect sparks safely away from the operator.

Question 2

What immediate action should an operator take if an abrasive wheel begins to vibrate excessively during use?

Accepted Answer

Stop the machine immediately and report the fault to a competent person

Answer

Excessive vibration may indicate imbalance, mounting problems, or structural damage to the wheel; the machine must be stopped immediately to prevent a potentially fatal wheel burst.

Question 3

Under what circumstances is it acceptable to grind on the flat side face of a straight abrasive wheel?

Accepted Answer

Never, unless the wheel is specifically designed and marked for side grinding

Answer

Straight wheels are not designed to resist lateral forces; side grinding induces stresses that can cause the wheel to crack or burst violently unless it is a type specifically engineered and marked for that purpose.

Question 4

What is meant by 'glazing' of an abrasive wheel?

Accepted Answer

The wheel face becoming smooth and polished, losing its cutting ability

Answer

Glazing occurs when abrasive grains become dulled and the wheel face appears smooth and shiny, making it ineffective at cutting and causing excessive friction and heat.

Question 5

What is the safest method for removing grinding dust and swarf from a bench grinder?

Accepted Answer

Use a vacuum extraction system or a damp cloth

Answer

Compressed air and dry brushing disperse fine grinding dust and potentially harmful metal or silica particles into the atmosphere; vacuum extraction or damp methods contain the dust safely.

Abrasive Wheels Practice Test

Abrasive Wheels Practice Test

Abrasive Wheels Training Certificate Work Rest Adjustment and Operating Techniques 3