Wear-Resistant & Heat-Resistant Flexible Welding Cable, Welding cable is a relatively large-diameter, single-core insulated cable, welding electrodes, ground clamps, and automated welding heads. Cables usually, but not always, have different colors so users can distinguish between the live wire and the ground wire. Welding cables have great flexibility and are soft but have strong abrasion- and oil-resistant insulation. Class K welding cables are rated at 600 volts. This welding cable comes in a range of colors including red, black, orange, yellow, green, and blue.