Metal Works 2, WASSCE (PC), 2017

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.



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.