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Question 5
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(5) (a) Sketch and label the following on a lathe cutting tool.
(i) rake angle;
(ii) clearance angle;
(iii) tool angle.
(b) Explain the difference between loading and glazing of a grinding wheel.
(c) State two uses of combination centre drill.
(d) State two reasons for the use of working drawings in design. |
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This question was well attempted by most of the candidates with good performance. The part that seems difficult for the candidates was part (b).
The required response to this part is given below:
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(b) Loading is a situation where the wheel has been used to grind soft metals and small particles become embedded in the wheel, while glazing is where the wheel has become blunt as a result of the bond not releasing the blunted grits.
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