Thin wall steel tube can achieve the goal of lower cost. Good looking of steel tubes is also important. The question is how to let good looking, standing high hydrostatic pressure, good corrosion resistance and thin wall steel tubes coexist? We can solve this problem. 1. Good Looking: We use good looking hot-dipped galvanized coil to make steel tubes then coated with transparent lacquer. The surface is close to electroplated coating. Black lacquer for black tubes. 2. Good Welding: We have good technique to weld thin wall steel together while making thin wall steel tubes. No leakage in the weld of steel tubes and can stand over 50 bar (700 PSI) hydrostatic pressure. 3. Good Corrosion Resistance: We use hot-dipped galvanized coil to make steel tubes and paint transparent lacquer on steel tubes. By using this way, the corrosion resistance is better than hot-dipped galvanized coating. For inner weld, we use patent inner weld galvanized painting technique to paint inner weld.