Also found in: Acronyms.
a device or mechanism used in machine building for the attachment, securement, and correct alignment of parts and modules. In individual and small-lot production, general-purpose assembly jigs are used, including plates, assembly beams, knife-edged supports, try squares, clamps, and jacks. A set of such jigs serves as a basis for constructing stands used in assembling modules and complete machines. In mass and large-lot production, specialized assembly jigs are used for securing major components and modules (rotating and multi-position jigs) and for accurate and rapid assembly of parts and modules (single-position, multiposition, stationary, and mobile jigs). Assembly jigs are also used for the preliminary deformation of elastic elements, such as coil and leaf springs and split rings, and for making connections with interference fit. In progressive assembly, jigs are used for varying the positions of the objects being assembled. The use of assembly jigs improves the quality of the items produced, facilitates the work of assemblers, and increases productivity.