Abstract: A metal heat exchange tube assembly for a fryer cooking channel of a hot oil fryer for food-process lines has a plurality of elongate, rectangular, longitudinally-extending heat exchange tubes with open inflow and outflow ends; a laterally-extending abbreviated rectangular inflow-manifold tube with a plurality of apertures in a sidewall; and a laterally-extending abbreviated rectangular outflow-manifold tube with the same. The plurality of heat exchange tubes are joined to the inflow-manifold and outflow-manifold tubes with respective alignment among the open ends of the heat exchange tubes and the apertures in the sidewalls of the manifold tubes. The heat exchange tubes comprise a composite construction of an elongate, square-U shaped channel having a web bottom wall and flange sidewalls of a given uniform thickness, and an elongate closure strip welded along spaced seams to the exposed upper edges of the flanges of the channel, thereby forming a thermal oil conduit.