Abstract: A press tool for forming a compressible mass into an annulus of given inner and outer diameters and axial length, the tool having radially movable outer and inner tool parts adapted to expand and contract, respectively, to form the mass to the desired inner and outer diameters. An axially movable annular member includes a working face for forming the compressible mass to the desired axial length. Each of the tool parts include a first array of radially movable members, each formed with a head having a working face curved to the desired diameter and a second interposed array of radially movable members also having a head having a working face. A central portion of the working face is curved to the desired diameter and opposed sloping outer portions are shaped for sliding against rear-faces of the heads of respective adjacent members of the first array.