A drill jig performs two important, repetitive jobs by holding the material and guiding the drill for holes. This simple tool helps assure accuracy when the same holes need to be drilled over and over. Jigs can come already made by a manufacturer, or they can be homemade. This drill press and hand drill accessory has lost its usefulness in manufacturing because of technological advances, but it remains popular in home wood shops.
There is no standard size or shape for a drill jig because it is custom made for an individual job. A jig is commonly made of a thin sheet of metal or wood and can be transported easily from project to project. All jigs have two distinct characteristics that never change: they always hold, and they always guide. There usually is a clamping system on the jig, either to clamp the wood in place to keep it from moving or to clamp the jig to the wood so that it doesn't move. After it is clamped, the jig has a series of holes in it that show the driller where to make incisions so that no matter how many pieces of wood are placed under the jig, their drilling patterns are all the same.
The jig normally comes to the user either prefabricated, or the drill operator must create a jig himself. A prefabricated drill jig guide commonly comes as part of a kit for a larger woodworking project. An example would be a simple jig that comes along with a set of instructions to create a cabinet. Using a drill and some ingenuity, experienced woodworkers who know that their projects will require repetitive drilling can create homemade jigs.
For as long as drills, either hand-cranked or mechanical, have been in use, this jig has helped ensure a consistent product. Drilling jigs have fallen out of popularity, especially in mass-production factory settings. Computerized mechanical tools such as the jig borer have eliminated the need for jigs because a drilling pattern can be programmed into a machine, and the pattern can be repeated as many times as necessary. This does not mean that the drill jig has become extinct, just that it is found primarily in the woodworking shops of amateur craftsmen. Jig borers are very expensive, so the drill jig will continue to be the guide for most home woodworkers.
By Patrick Wensink