A method and apparatus for making prosthetic socket preforms, a method for making prosthetic sockets, and a socket attachment component are disclosed. The method of making preforms of the present invention involves the blowmolding of memory plastics with a cooling step prior to parison expansion to enhance the molded-in stresses of the resulting preform. The blowmolding apparatus of the present invention comprises two mold halves having specially designed knifing sections and a modified blow pin. The method for making prosthetic sockets involves heat- and vacuum-forming memory plastic preforms over a positive cast of a residual limb after preheating of the cast to prevent heat-sinking. The socket attachment component disclosed is adapted for molding with a prosthetic socket during heat- and vacuum-forming, is configured to receive a sleeve attachment shaft, and possesses an integral male member for attaching the component and socket to an artificial limb shaft using bolts or screws.