Abstract: A means and method or process are described in which a sample of solid curable elastomeric material, such as raw or compounded vulcanizable rubber or equivalent, is worked or shear stressed between dies which hold its opposite faces firmly while one of them is gyrated or moved in a small-diameter path about the axis of the other. By this means, a continuous shear stress is applied to the sample over its entire transverse area, there being no relaxing or reversal of the applied forces as in the conventional oscillating systems. The apparatus comprises an upper die, mounted for axial movement towards or away from a lower die whose central vertical axis is slightly offset from the axis of the former. Elastic means bonding the lower die to its mount prevent its rotation but permit flexing and shifting laterally as the lower die is rotated or gyrated in a small circle about the axis of the upper die.