Fin is pressed by fin press line and end plate is pressed by power press line as pretreatment, while bending, cutting, and twisting the aluminum tube by Auto Al Tube Bending Machine and Skew and folding Flattening Machine . Then the pipe is inserted by and expanded by Double Station Insert Tube and Expanding Machine to fit the pipe with the fin. After that, the interface is welded by Cooper Tube and Aluminum Butt Welding Machine and the end plate is assembled by Side Plate assembly Machine. After detected by Water Leakage Test Machine, the unit is degreased by washing machine and Blowing Device.