A coupling apparatus for adjustably mounting modular tooling members having a base member releasably connectable to a slide mount wherein said base member is adjustably located along a predetermined 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. In a preferred embodiment, the midportion may also be rotatably adjustable with respect to an end member along a second rotational 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. In an alternative embodiment, the midportion is integrally connected to the end member wherein the end member provides an aperture for matingly engaging a first spline rod. The first spline rod may be rotatably adjusted about a second rotational axis. A spline bracket may be adjustably connected to the opposite end of the first spline rod while also engaging one end of a second spline rod. The spline bracket provides rotational adjustment of the two spline rods wherein the axes of the spline rods are substantially perpendicular and axially spaced from one another. A workpiece mounting bracket having a base member, midportion, and end member, may then be used to matingly engage and adjustably connect the second spline rod to a workpiece handling device.