In the manufacture of structures made of pipes of the same diameter to neverlet holes in them easily and quickly will help here’s a simple jig. It consists of a metal plate and wooden block in advance which is made a longitudinal cut. In the bar there are several vertical through-holes for drill bits of different diameters. Thanks to the conductor drill bit will not slip off from the pipe, and therefore do not need to do this pre-ncarnate the place of drilling.