Abstract: A heat exchanger assembly includes a first header having an inlet and a second header having an outlet spaced parallel from each other. A plurality of tube members having an ultimate strength (Us) and a width (w), extend between the first header and the second header. The tube members define a plurality of fluid passages for the flow of a liquid through the tube members and between the first and second headers. The tube members extend through at least one bend having a bend radius (r) in the range of 50.00 mm to straight (?) through angles between 0 and 100 degrees. A plurality of corrugated air fins are brazed between adjacent tube members. The bends of the tube members satisfy a bending formula (w/r)Us?30 mega Pascal.