Fitting and Machining - Precisely Remove Metal to Make Useful Things

Turning is a machining process in which a cutting tool, typically a non-rotary tool bit, moves more or less linearly while  the work piece rotates. Turning can be done manually, in a traditional form of lathe, or by using an automated lathe.  When turning, a piece of relatively rigid material is rotated and a cutting tool is traversed along axes of motion to produce precise diameters and depths. Turning can be either on the outside of the cylinder or on the inside (also known as boring) to produce tubular components of various geometries.  The turning processes are typically carried out on a lathe, considered to be the oldest machine tools, and can be of four 

different types, namely straight turning, taper turning, profiling or external grooving. These types of turning processes  can produce various shapes of materials such as straight, conical, curved or grooved work pieces. In general, turning uses simple, single-point cutting tools. Each group of work piece materials have an optimum set of tool angles which have been developed through the years. 

Milling operates on the principle of rotary motion. A milling cutter is spun about an axis while a work piece is advanced  through it in such a way that the cutters are able to shave chips of material. This non-continuous cutting operation means that no surface cut by a milling machine will ever be completely smooth; at a very close level (microscopic for very fine feed rates), it will always contain regular ridges.

The following topics, skills and concepts are learnt and developed from grade 10 through to grade 12: