Abstract: A multiple hole gauging tool for use with a variety of straight-edge members, comprising an elongated rod having a transverse slot aperture therethrough for slidably receiving a straight-edge member therethrough, a threaded stud member at one end of the rod adjacent the slot aperture, a cap member threadedly carried by the stud member and being tightenable against the straight edge for locking the rod at a selected position along the straight edge, the cap member having a cylindrical hole engagement surface around the outer periphery thereof. The rod member is provided with a window aperture for reading indicia on the straight edge while the outer surface of the cap member comes in several different sizes to fit different diameter holes. Insert members are provided for effectively changing the size of the aperture to accommodate different size straight edges.