A jig is a work-holding device that holds, supports, and locates the workpiece and guides the one or more tools to perform a specific operation.

A fixture is a work-holding device that only holds, supports, and locates the workpiece, but does not guide the tools to perform a specific operation.

The working of metals below their recrystallisation temperature is known as cold working. Most of the cold working processes are performed at room temperature. The cold working distorts the grain structure and does not provide an appreciable reduction in size. It requires much higher pressure than hot working. The extent to which a metal can be cold worked depends upon its ductility. The higher the ductility of the metal, the more it can be cold worked. It also increases tensile strength , yield strength and hardness of steel but lowers its ductility. The increase in hardness due to cold working is called work-hardening.

The cold working of metals is carried out below the recrystallisation temperature.