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

1 mm

Answer

3 mm

Answer

10 mm

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

Reduce feed pressure and continue grinding carefully

Answer

Increase grinding pressure to stabilise the wheel against the workpiece

Answer

Switch to a lighter workpiece to reduce the load on the spindle

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

When grinding large flat workpieces that cannot be presented otherwise

Answer

When the wheel is new and has maximum structural thickness

Answer

When additional face-shield protection is worn by the operator

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

The wheel surface becoming wet or contaminated with cutting oil

Answer

A surface crack forming across the face of the wheel

Answer

The wheel developing an uneven or out-of-round profile

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

Blow it away with a compressed air line

Answer

Brush it away with a stiff dry brush

Answer

Wipe with a dry cloth and dispose in a general waste bin

Question 6

Why is grinding aluminium or other soft non-ferrous metals on a standard bench grinder particularly hazardous?

Accepted Answer

The soft metal clogs the wheel's pores, risking loading, overheating, and wheel failure

Answer

Non-ferrous metals produce highly toxic sparks during grinding

Answer

Non-ferrous metals require a higher wheel speed than standard wheels are rated for

Answer

The material can become magnetised and attract metal debris to the wheel

Question 7

Which of the following describes the correct way to present a workpiece to a bench grinder wheel?

Accepted Answer

Into the downward rotation at the front of the wheel, supported on the work rest

Answer

Against the direction of wheel rotation at the top of the wheel

Answer

From directly above, pressing the workpiece down onto the top of the wheel

Answer

From any convenient angle, provided the work rest is in contact with the workpiece