Modern industrial needs call for the manufacture of highly sophisticated, multi-strand, composite components which may be required in such diverse applications as the chemical industry, off-shore oil installations, nuclear plant, pressure vessels, fluidised beds, cryogenic systems and permanent storage of computer data. Conventional production techniques of such components become more difficult to apply as the material and geometrical complexity of the multi-strand composite increases, and the problem of integrity and homogeneity of the structure acquires an overriding importance. This is particularly so with the axisymmetric assemblies—intended for heat exchangers, remote control rods, transition joints and light, but strong, laminated or mesh-reinforced pressure vessels—in which structural integrity may well have to be combined with good anti-corrosive heat transfer, high pressure and, possibly, the high temperature characteristics of the finished product. In a number of applications, particularly in the field of atomic energy, the more “exotic” refractory metals are not always available in bulk form and therefore components have to be manufactured out of compacted powders, short-length rods and similar prefabricates. This may preclude the possibility of employing standard metal-forming operations and, again, may call for an unconventional approach. A possible solution to these manufacturing difficulties is found in the implosive welding of assemblies and geometrically prearranged arrays of different materials which would then form integral structures. Where required, a more conventional post-welding processing, such as drawing or extrusion, can follow and will be made easier by the lessening of the differentially in metal flow. Additional advantages of an implosive or explosive operation lie in its ability to provide efficient and complete joints on curved surfaces, and to effect the welding in combinations of materials that, conventionally, are often incompatible. This investigation assesses the technological aspects of the hydrostatic extrusion of implosively prewelded arrays of mild steel/copper assemblies to determine the optimum conditions that produce a high-quality final product. The chosen material combination is, in itself, of no particular practical significance, but conveniently represents the use of two basic engineering alloys of different material properties. Hydrostatic extrusion of such composites serves the double purpose of sizing without affecting the basic properties of the prefabricate. It improves the homogeneity of structure without impairing the quality of the weld. With reductions of up to 45%, and the volume fraction of copper varying from 0.08 to 0.92, the strength of the weld in shear is between 100 MPa and 400 MPa, while the tensile strength of the composite is in the range of some 400 MPa to 700 MPa.