The pressure for molding and its influence on the electrostrictive characteristics of PMN ceramics, and the sintering deformation of the cylinder made from the ceramics are studied. The ceramics cylinders will be used as raw materials of the active high rigid bearings of the gear rolling tester which authors intend to construct. The followings are obtained: (1) The good density and the good electrostrictive characteristics are obtained under the pressure lower than 45% of the limit pressure at which some cracks appear in the ceramics cylinder pushed out of a mold. (2) The formulae which can describe the shrinking deformation of ceramics cylinder are obtained under the assumption of the elastic deformation of ceramics cylinder. (3) The shrinking deformation is controlled by using the cylinder base of the same material as expected from the studies with the formulae.
