Shanghai Jinshi Suotai Mechanical & Electric Equipment Co., Ltd. Designs and manufactures all kinds of finned tubes. 1, ... , copper, copper alloy, titanium and so on. 2, fin: aluminum (extruded type or wound type), steel (wound type, high frequency welding ... ", OD38; 2, fin: OD34, OD44, OD57, OD70 (or by request). extruded fin tube