Abstract: An apparatus for producing high pressure comprises a multi-die system (1). Each die (2) is made up of two cooperating parts arranged along a longitudinal centerline (3) of the die (2), one part being a working body (4), the other being a base member (8). The working body (4) is also made up of two parts in the direction essentially perpendicular to the longitudinal centerline (3) of the die (2), the parts being a central insert (21) and an encircling ring (22) both arranged coaxially and capable of relative displacement towards a test sample (7). The surface area of an end (23) of the central insert (21) of the working body (4) approximates to or less (in this case less) than the surface area of the central portion (18) of an end (11) of the working body (4). An end (5) of the working body (4) is arranged for direct cooperation with a solid medium (6) which is plastic under pressure and serves to surround a sample (7) being tested.

Abstract: A device for building-up high pressures, in which the die surfaces facing each other are provided with circular grooves intended to be filled with a solid medium and arranged concentrically to, and beyond, the central sections of the dies. On closing of the dies, these circular grooves form spaces filled with the solid medium.