Abstract: A definitive socket for residual limb prosthetic use is formed in a single molding step by compressive pressure casting or molding a pre-formed, moldable, hardenable socket material over a residual limb and curing the socket material to a load-bearing hardened condition while it is maintained under peripheral compressive pressure against the residual limb and while the residual limb is tensioned in a distal direction during the casting process. The combination of pressure casting the socket material and applying tension to the residual limb in a distal direction while the socket material is curing results in forming a definitive socket that fits well to the residual limb after curing without substantial rectification. Pressure relief formations, socket coverings, and a prosthesis coupler may be compression molded simultaneously with the socket.