Question 5
(a) State two stages in sand casting.
(b) Explain casting defects
(c) State the use of the following lathe turning tools:
(i) knurling tool;
(ii) parting off tool;
(iii) thread chaser;
(iv) boring tool.
Observation
The expected responses are as given below:
5(a) Stages in sand casting
- Pattern preparation
- Mould preparation
- Melting of metal
- Pouring of metal
- Removal of casting
- Fetting of casting
- Machining of casting
(b) Casting defect is an undesirable feature which occurs in casting.
(c) The uses of the following lathe tools:
(i) knurling tool is used to produce impression on the surface of the workpiece to give a firm hand grip.
(ii) parting off tool is used for cutting off metal on the lathe.
(iii) thread chaser is a lathe accessory used to finish thread cuts to shape on the lathe.
(iv) boring tool is used on the lathe to enlarge drilled hole.