A jig for drilling all the dowel and fixture mounting holes for the 32 mm system of cabinet construction consisting of a pair of parallel rails having face and side, a third rail identical to the two parallel rails and attached perpendicularly to the parallel rails, a saddle which straddles the rails and containing a bushing that fits through the saddle and into the holes of the rails and two asymmetric clamping frames having a clamping thumbscrew and a locating thumbscrew with a thread cut on a 1 mm pitch that rigidly attaches to one of the rails.