A coupling apparatus for adjustably mounting modular tooling members having a base member releasably connectable to a slide mount wherein the base member is adjustably located along a predetermined linear path of travel defined by the slide mount. The base member is rotatably adjustable with respect to a midportion via a pair of matingly engaging contoured surfaces. The contoured surfaces are substantially circular having V-shaped teeth extending radially outward. The V-shaped teeth of the contoured surfaces matingly engage and are secured by fasteners to prevent any radial movement of the midportion with respect to the end member. The midportion may also be rotatably adjustable with respect to an end member along a second centerline axis. The midportion and the end member may be adjustably rotated through a pair of contoured surfaces substantially similar to that provided between the midportion and the base member. The end member provides an aperture for releasably connecting a boom rod to the end member.