Abstract: A work holding system for repeatably holding work pieces in a very precise position and orientation for machining operations or the like to be performed thereon. The work holding system comprises a cooperating receiver and pallet assembly. The receiver is mounted on a suitable surface. A work piece is mounted on the pallet. A cooperating pair of matable male and female polygons are provided, one mounted in the receiver and the other mounted in the pallet. The pallet and the receiver have cooperating, abuttable, annular surfaces. The pallet is mountable on the receiver with the male and female polygons mated to repeatably provide highly precise concentricity or centering of the work piece and the pallet with respect to the receiver. The abutment of the annular surfaces of the receiver and pallet assures highly precise, repeatable flatness or parallelism of the pallet with respect to the receiver so that the receiver axis and the centered pallet axis are coaxial.