Abstract: A baffle support fixture for a machine for assembling automatically the tubes and baffles of a shell and tube type heat exchanger. The heat exchanger has the usual plurality of metallic tubes and perforated baffles through which the tubes pass. The baffles are non-metallic, and are composed of a soft and pliable or flexible gasket-like material. The machine is provided with a tube and baffle holding fixture mounted on a selectively movable work table. Opposing, horizontally spaced rods transmit selected quantities of tubes successively from a tube supply to the fixture and insert the tubes through the perforations in baffles supported vertically by the fixture. A pair of rigid, vertical, closely spaced plates stabilize each of the non-metallic baffles during the tube insertion cycles. Following each deposit of a selected number of tubes in the baffles supported by the fixture, the work table is adjusted prepatory to the transmission of the next selected quantity of tubes to the fixture.