Fixture Design

A fixture is a device for locating, holding and supporting a workpiece during a
manufacturing operation. Fixtures are essential elements of production processes as
they are required in most of the automated manufacturing, inspection, and assembly
operations.
Fixtures must correctly locate a workpiece in a given orientation with respect to
a cutting tool or measuring device, or with respect to another component, as for
instance in assembly or welding. Such location must be invariant in the sense that
the devices must clamp and secure the workpiece in that location for the particular
processing operation.
There are many standard workholding devices such as jaw chucks, machine
vises, drill chucks, collets, etc. which are widely used in workshops and are usually
kept in stock for general applications.
Fixtures are normally designed for a definite operation to process a specific
workpiece and are designed and manufactured individually. Jigs are similar to
fixtures, but they not only locate and hold the part but also guide the cutting tools in
drilling and boring operations. These workholding devices are collectively known
as jigs and fixtures.