The process of manufacturing a coil begins with a rugged heavy gauge steel case.  The case parts are produced on modern CNC equipment or with high volume hard tooling.  Standard case material is galvanized steel, but copper, aluminum and stainless cases are also available.

The heart of the heat-transfer surface is the plate fin.  A roll of thin sheet material is fed into a high-speed die press, where it goes through a 7-step progression that transforms it into a high-tech heat transfer surface.  The fin material may be between .0045" and .010" thick depending on the required application.  Available fin materials are aluminum and copper.

Rolls of seamless copper tubing are fed into the hairpin bender, where they are first straightened, then cut to length and bent 180°.  These "hairpins" are later inserted into the fins to form the circuits for the heat transfer fluid.