what is the purpose of machining?

(a) Purpose of Machining 

Most of the engineering components such as gears, bearings, clutches, tools, screws and nuts etc. need dimensional and form accuracy and good surface finish for serving their purposes. Preforming like casting, forging etc. generally cannot provide the desired accuracy and finish. For that such preformed parts, called blanks, need semi-finishing and finishing and it is done by machining and grinding. Grinding is also basically a machining process. Machining to high accuracy and finish essentially enables a product
                                  • fulfill its functional requirements
                                  • improve its performance
                                  • prolong its service