Producing the international standard DYC Aluminum Tube needs real accuracy in the process of molding. And it has Precise Roundness, Straightness, Concentricity and Roughness by Control of thickness Variation during extrusion process. and Drawing Process. The low Temperature Hard Anodizing Improve Roughness and Coating hardness in the DYC tube surface. That is able to minimize abrasion of seal and have real accuracy work and long life for DYC tube.