refers to any device that is used to a secure a workpiece against the forces of machining. The most basic workholding device is a simple clamp, but workholding can also involve complex fixtures that are custom-built for particular parts.
Other common workholding devices include vises and chucks, as well as indexers or rotary tables that are able to change the part’s position while it is held, so the machine can reach various features. In most machining applications,
workholding also locates the part. On a machining center, for example, a vise or fixture may also provide the precise position and orientation where the machining program expects to find the workpiece