Abstract: A method and apparatus for lacing hairpin tubes into plate fin bundles by the continuous movement of plate fins from one end of horizontally supported guide rods to the other end thereof where they pass onto aligned tubes. The horizontal guide rods are precisely positioned by a number of clamps applied along their lengths. Provision is made to successively remove and reapply the clamps in such a way as to permit the selective movement of the fins along the guide rods while maintaining the guide rods in their fixed positions. The guide rods are graduated in various diameters to facilitate the easy movement of the plate fins and hairpin tubes thereon while providing for precise relative placement of the plate fins and the hairpin tubes.