Swivel tips have ball jointed swivel heads to compensate for minor misalignment and to eliminate marking of the work surface. They are all machined from Class 2 (Tuff 77) alloy bar stock. The S and SS series electrodes water hole does not reach the head. In the OS and OSH style electrodes the water does contact the head and an O-ring is used to seal the head. In the SS Series electrode a spring is used to keep pressure on the head for better positioning. Class 1 (Tuff 88) and Class 3 (Tuff 55) heads are also avalible upon request.