2. To increase the production.
3. To assure high accuracy of the parts.
4. To provide for interchangeability.
5. To enable heavy and complex- shaped parts to be machined by being held rigidly to a machine.
6. Reduced quality control expenses.
7. Increased versatility of machine tool.
8. Less skilled labour.
9. Saving labour.
10. Their use partially automates the machine tool.
A jig may be defined as a device which holds and positions the work, locates or guides the cutting tool relative to the workpiece and usually is not fixed to the machine table. It is usually lighter in construction.
A fixture is a work holding device which only holds and positions the work, but does not in itself guide, locate or position