Jigs and fixtures are the special-purpose tool which is used to facilitate production (machining, assembling and inspection operations) when the work piece is based on the concept of interchange ability according to which every part will be produced within an established tolerance. Jigs and fixtures provide on means of manufacturing interchangeable parts since they establish a relation predetermined to tolerance between the work and cutting tool. They eliminate the necessity of a special set up for each park. So, a jig is a device which holds and positions the work; locates or guides the outing tool relative to the workpiece and usually not fixed to the m/c table. It is usually lightly in construction.

A fixture is a work-holding device and position the work; but doesn't guide, locate or position the cutting tool. The setting of the tool is done by machine adjustment and a setting blocker using slip gauges. A fixture is held or clamped to the machine table. It is usually heavy in construction.

Jigs are used on drilling, reaming, tapping and boring operations, while fixtures are used in connection with turning, milling, grinding, shaping, planning and boring operations. The use of jig and fixture makes possible more rapid and more accurate manufacturing at a reduction of cost.