API STD661 Aluminum spiral finned tubes applicated for air cooler and heat exchanger Specifications Bare tube material: (1) Carbon steel tube SA179, SA334, SA214, SA106B, GB8163, GB9948, GB3087,10#, 20#, (2) Stainless steel tube SA789, SA213, SA312, SA210, SA249, 304, 316, T11, T22, T91 (3) Copper tube C1100, C12200, C44300, C68700, C70600, C71500, CuNi90/10, 70/10,70/20,70/30 etc. Fin Length:130mm~180m Fin OD:25mm~82mm Fin/inch: 5-12 Fin thickness: 0.2mm~1mm Fin height: 3mm~16.2mm Fin material: aluminum 1060, 1050, 1070 Fin type: extruded Function (1)Energy conservation; (2) Long time using; (3) Light than steel fin; (4) High heat transfer; Copper C1100,C12200 extruded finned tubes, spiral fin tubes for air condenser and heat exchanger