Introduction

The shaping of materials before they are incorporated into a product usually occurs in a number of stages. Specific examples of the shaping processes used to produce five different parts are illustrated in Fig. 1.1 (a) and an outline of the main groups of shaping processes is shown in Fig. 1.1 (b). It will be seen that some parts which have been cast, sintered or moulded can be incorporated directly into assemblies without further processes, although usually machining is required. Primary forming operations produce a range of products such as forgings, bar, plate and strip, which is either machined or further formed in the factory. Some factory formed parts, however, still have to be machined before they are assembled. Fig. 1.1 (a)Typical shaping processFig. 1.1 (b)Main subdivisions in metal shapingFig. 1.2Stages in specification of process