Abstract: A thick tube welder for welder together a tubular end fitting and a tube. The end fitting and the tube are placed in axial alignment within a welding head housing with the end fitting being located in a mounting housing. The mounting housing is then fixedly secured to the welding head housing. An inner welding electrode is connected to the mounting housing and is located in alignment with the inner surface of the welding joint. An outer welding electrode is located in alignment with the exterior surface of the welding joint with this electrode being mounted on the welding head housing. Both electrodes are rotatably driven either simultaneously or in sequence in order to create the weld between the tube and the end fitting. Depending on the length of the end fitting, the inner welding electrode is to be adjustable longitudinally relative to the welding joint.