Abstract: Injection nozzle apparatus comprises inner and outer body portions. The inner body portion includes a melt channel and the outer body is made of a pressure resistant material. The ratio between the inner diameter of the outer body portion and the outer diameter of the inner body portion is selected so that a pre-load or a load is generated when assembling the outer body over the inner body. Preferably the assemble of the two bodies is removably fastened to an injection nozzle body. Preferably the inner body comprises a material with wear resistant characteristics to withstand abrasive or corrosive molten materials. The apparatus of the present invention is particularly useful in molding machines and hot runner nozzles for high pressure molding of various materials at normal or elevated injection temperatures.