The strip material is subjected to controlled deformation under tension giving the optimum contact pressure of the foot of the fin onto the base tube thus maximising the heat transfer properties. The foot of the fin considerably enhances the corrosion protection of the base tube.

Manufactured in the same way as the 'L' finned tube type except that the fin foot is overlapped to completely enclose the base tube thereby giving excellent corrosion resistance. This type of finned tube is often used as an alternative to the more expensive extruded type fin in corrosive environments.

Manufactured exactly as the 'L' finned tube except that the base tube is knurled before application of the fin foot. After application, the fin foot is knurled into the corresponding knurling on the base tube thereby enhancing the bond between the fin and tube, resulting in improved heat transfer characteristics.

The fin strip is wound into a machined groove and securely locked into place by back filling with base tube material. This ensures that maximum heat transfer is maintained at high tube metal temperatures.

This fin type is formed from a bi-metallic tube consisting of an aluminium outer tube and an inner tube of almost any material. The fin is formed by rolling material from the outside of the exterior tube to give an integral fin with excellent heat transfer properties and longevity. Extruded fin offers excellent corrosion protection of the base tube.