Abstract: The invention relates to a profiled part (12) for a heat exchanger, configured to have at least one fluid flow tube (14) passing through it, comprising, for each flow tube (14), a hollow cylinder (18) comprising an inner surface configured to receive said flow tube (14), the cylinder (18) having an inner diameter which is substantially equal to the outer diameter of said flow tube (14). The profiled part (12) is characterized in that the profiled part comprises a slit (16) extending over the whole length of the cylinder (18) and configured to permit, by application of at least one mechanical force to the profiled part, a modification in the inner diameter of the cylinder (18) in order respectively to permit the insertion of the tube into the cylinder (18) or the clamping of the tube (14) by the inner surface of the cylinder (18). The invention also relates to a heat exchanger (10) comprising such a profiled part (12) and a flow tube (14).