Metal cutting

             All metal cutting operation basically involve forcing a cutting tool with one or more cutting edges progressively through the excess material on the work piece.The work piece and the tool are securely held in a machine tool and its accessories while power is supplied to provide relative motion between the tool and work piece.This results in removal of any excess material interfering with the relative motion in the form of chips. metals are cut primarily to produce surface of desired shape, accuracy or surface finish depending upon their use.
            Other application of machining relate to production of certain surfaces and shapes such as holes, centers and threads not exciting in work pieces or to removal of burrs, sharp edges etc for better appearance or safety.
            Since all machining involves considerable amount of labour , cost and loss of material as chips, machining should never be overdone to the extent of producing surfaces which are more accurate or better finished than required for proper  functioning of the product.

Metal cutting processes:-
(1)Turning
(2)Drilling
(3)Boring
(4)Reaming
(5)Shaping
(6)Planing
(7)Slotting
(8)Milling
(9)Abrasive machining
(10)Sawing

             When dimensional accuracy or surface finish better than that obtainable by conventional metal cutting processes are desired the same can be obtained with surface finishing processes which include the following
(1) Lapping
(2)Honing
(3)Superfinishing
(4)Polishing
(5)Buffung
(6)Roller burnishing
              These processes use abrasive grains in different forms to produce the required surface characteristics except roller burnishing which is a cold working processes.