P740 Engineering and Metalwork

Materials:

Further insight into the working properties and characteristics of ferrous and non-ferrous metals and their alloys. Identification by common workshop tests and their suitability for working by the various methods available including: casting, rolling, drawing, extruding, pressing, spinning and machining.

Test of Materials

(a) A basic understanding of the terms used in tensile, impact, hardness and bending tests so as to compare the various properties with specifications of the different materials.

(b) A deeper understanding of:

(1) The heat treatment of ferrous metals including the process of annealing, normalizing, hardening and tempering case-hardening.

(2) The internal structural changes of low and high carbon steels resulting from heat treatment.

(3) Work hardening effects and fatigue in the engineering of components.

(c) Cutting tool angles and their effect on the cutting action and efficiency when cutting various materials.

Measuring and Testing

General marking out procedure and the use of vernier height gauge reading to 0.02 mm and of inside and outside micrometers, depth gauge, telescopic gauge, dial indicator, plug and gap gauges with an understanding of their use, including the importance of tolerance and allowance in ensuring quantity production and interchangeability of parts. Use of protractor, vernier gauge and combination square. The use of jigs, fixtures and silver steel dowels.

Machining Process

(a) A deeper understanding of the drilling machine including the pillar drilling machine. The use of radial and multi-spindle drilling machine.

(b) Further use and understanding of the center lathe including the use of the three- and four-jaw chuck, face-plate, collect chunk, mandrels, steadies, boring, parting off and taper turning with the relative calculations and including an understanding of tailstock off-setting and taper-turning attachment methods.

(c) Screw-cutting on the lathe including the calculations necessary for selection of the change wheels.

Shaping

The construction and use of the shaping machine. The processes of setting up work on the machine table in the machine vice; producing surfaces square and parallel to each other; angular cutting and vertical cutting.

Milling

Elementary principles associated with the construction and use of the plain horizontal universal milling machine. The processes of setting up work on the machine table and in the machine vice; producing surfaces square and parallel to each other. Construction and use of the vertical milling machine. Work sould be limited to the use of the following cutters: cylindrical (slab), side and face, slotting and slitting saw.

Grinding

Correct choice and fitting of grinding wheels. Grinding techniques of the common cutting tools. Elementary knowledge of the horizontal universal grinding machine as applied to grinding of flat and cylindrical surfaces.

Foundry Work

The design and making of various methods of casting in non-ferrous metals, including green sand moulding, core-box and core-making, the use of one-piece patterns, split patterns and cores, the characteristics of good patterns. The construction and management of the gas-fired crucible or pot furnace. The correct handling and safe use of foundry tools and equipment. The identification of and remedies for common faults in castings.