Noun
English Wikipedia has an article on:jig borerWikipedia
jig borer (plural jig borers)
A type of machine tool invented during the World War I era to make possible the quick-yet-very-precise location of hole centers.
In many cases, a jig borer is a "jig eliminator." In other words, such a machine may be used instead of a jig either when the quantity of work is not large enough to warrant making a jig or when there is insufficient time for jig making. Franklin D. Jones