Abstract: The present invention relates to a device for moulding cylindrical pieces, comprising, on the one hand, a tube made of a rigid, elastic material, split longitudinally and tending to expand transversely under the action of its inherent elasticity and, on the other hand, holding members capable, when they cooperate with said tube, of obliging the internal cavity thereof to take a reduced section corresponding to that of said pieces to be moulded and, when they do not cooperate with said tube, of allowing said internal cavity to take an expanded section. The invention is more particularly applicable to the moulding of tubular pieces, particularly from a laminate of supple fabric impregnated with polymerizable resin.