View source for Jig (tool)

{{confused|Fixture (tool)}}
{{Short description|Custom-made tool used to control the location and/or motion of another tool}}
{{More citations needed|date=February 2010}}
[[Image:Frame building jig.jpg|thumb|right|A bicycle frame building jig]]
A '''jig''' is a type of custom-made [[tool]] used to control the location and/or motion of parts or other tools.

==Description==
[[Image:Bundesarchiv Bild 183-76109-0001, Werktätige des Fritz-Heckert-Werk-Karl-Marx-Stadt.jpg|thumb|right|Device with grooves and [[chuck (engineering)|chuck]]s]]
A jig's primary purpose is to provide [[repeatability]], [[accuracy]], and [[interchangeable parts|interchangeability]] in the [[manufacturing]] of products.<ref>{{harvnb|Henriksen|1973|p=1}}.</ref> 

An example of a jig is when a key is duplicated; the original is used as a jig so the new key can have the same path as the old one. Since the advent of [[automation]] and [[computer numerical control]]led (CNC) machines, jigs are often not required because the tool path is digitally programmed and stored in memory. Jigs may be made for reforming plastics.

Jigs or templates have been known long before the industrial age. There are many types of jigs, and each one is custom-tailored to do a specific job.

==Drill jig==
A ''drill jig'' is a type of jig that expedites repetitive hole center location on multiple [[interchangeable parts]] by acting as a template to guide the [[twist drill]] or other boring device into the precise location of each intended hole center. In metalworking practice, typically a hardened [[drill bushing]] lines each hole on the jig plate to keep the tool from damaging the jig.

Drill jigs started falling into disuse with the invention of the [[jig borer]].

Since the widespread penetration of the manufacturing industry by CNC [[machine tool]]s, in which [[Servomechanism|servo]] controls are capable of moving the tool to the correct location automatically, the need for drill jigs (and for the jobs of the [[Drill#Drill press|drill press]] operators who used them) is much less than it used to be.

==See also==
*[[Jig grinder]]
*[[Staircase jig]]
*[[Sharpening jig]]
*[[Tapering jig]]

==References==
{{Reflist}}

===Bibliography===
*{{Citation | last = Henriksen | first = Erik Karl | title = Jig and fixture design manual | publisher = [[Industrial Press]] | year = 1973 | url = https://books.google.com/books?id=OX9hspFzRAsC | isbn = 978-0-8311-1098-7 | postscript =.}}

{{Measuring and alignment tools}}
{{Woodworking}}
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[[Category:Woodworking jigs]]
[[Category:Woodworking tools]]
[[Category:Metalworking tools]]