PLASMA ARC TORCH AND METHOD FOR IMPROVED LIFE OF PLASMA ARC TORCH CONSUMABLE PARTS

A plasma arc torch and method for improving the life of the consumable parts of the plasma are torch, including the electrode, the tip and the shield cap. The method includes turbulating gas as it flows over the exposed surfaces of the electrode, tip and shield cap to increase turbulence in the hydrodynamic boundary layer of the gas flow, thereby enhancing convective heat transfer. The result of enhanced cooling is improved consumable parts life. For example, to increase the turbulence of the gas flow over the outer surface of the electrode, the plasma arc torch electrode has a roughened, or textured outer surface formed with dimples, axially extending grooves or spiraling grooves formed in the outer surface of the electrode. The inner and outer surfaces of the tip and the inner surface of the shield cap are similarly textured.