Abstract: Disclosed herein is a holding clamp assembly disposed on a table having parallel trackways disposed thereon. Riding within these trackways are diverse types of clamping mechanisms which cooperate and coact with one another to provide retention means for objects to be worked on. In one embodiment, the clamping devices comprise opposed parallel faces which engage the object to be worked on. Another embodiment the clamping mechanism is defined by L-shaped clamps having clamping screws disposed at one extremity to engage a work piece between the table surface and the screw clamp.