A positionable vacuum clamp system including a vacuum table and one or more positionable vacuum clamps which can be of various shapes to accommodate differently shaped workpieces. The positionable vacuum clamp(s) align to the vacuum table having a recessed grid. Each positionable vacuum clamp includes a base plate and a positionable center plate and attached top plate slidingly secured by a retainer washer to the base plate. Vacuum passages within and about the positionable vacuum clamp communicate between the vacuum table and the upper vacuum mating structure of the top plate to vacuumingly secure a workpiece to the top plate for subsequent machining by external equipment.