The components of cryostats are interconnected by means of tension members which are frequently made from a fiber glass reinforced plastic material. Such members, which exhibit a rectangular cross-section and bores for receiving the mounting bolts have shown to be not fully reliable because they tend to break easily in the areas of the bores. Consequently, loop-like tension members have been frequently used; but their production is expensive and connected with considerable production tolerances. The invention proposes to use a tension member which is cut out from a plastic sheet material reinforced by a fiber glass weave, and which comprises an elongated portion (21) with parallel edges, followed on both ends by enlarged areas (22) with bores (25) for the mounting bolts. The transition between the central area (21) and the enlarged areas (22) is formed by a transition portion (23) with arc-shaped edges (24). The tension members can be fastened directly on the walls of the components to be interconnected, by means of screws. The resilience of the sheet material enables spaces directed vertically to the plane of the sheet material of the tension member to be bridged.