Question 4
(a) (i) What is a fastener?
(ii) List the steps involved in riveting.
(b) (i) Sketch a countersunk head screw.
(ii) Where is countersunk head screw mostly used?
(c) (i) What is the purpose of swage in a forging process?
(ii) List three tools used to prepare metal surface before welding.
Observation
Most of the candidates could not sketch countersunk head screw and could not state its area of application. The correct responses are given below.
4a. (i) A fastener is a device used to hold pieces of work together.
(ii) Steps involved in riveting are
- selection of suitable rivets;
- marking out the points;
- centre punching;
- drilling holes at the points;
- rivetting the workpieces.
(ii) Countersunk head screw is used
- in confined places where bolts and nuts do not have access.
- where the head has to flush with the surface of the work.
(c)(i) The swage is used
- for changing the sectional shape of work to round or hexagonal form;
- to finish round or hexagonal shaped workpiece.
(ii) Three tools used to prepare metal surface before welding are
- wire brush;
- file;
- scraper.