Component having a hollow cross-section

The invention relates to a particularly long component (1), with a closed, roughly channel-shaped hollow cross-section, such that said component may support large forces in various directions and is suitable as a support. The component comprises two individual parts (3) and (4), which have two contact patches (2) with each other, running in the longitudinal direction. At least one first part (3) of the both parts thus has a U- or channel-shaped cross section and is in working connection to the second part (4) which closes the first as a form of lid. The first part (3) is a metal profile (5), extrusion-coated on at least one side with a plastic layer (6) which increases the section modulus and is thus multi-layered. Said plastic layer (6) extends to the edges (7) of the first part (3) and forms there a contact patch for the second part (4). The second part (4) is made from plastic and in the working position is welded to the plastic layer (6) at the contact patch. A stiff component (1) is thus produced with a hollow cross-section, making common use of the advantages of metal and plastic.