Abstract: This invention relates to a coupling comprising female and male members (19, 18) having co-operating wedge surfaces (20,21), which may be urged into contact by tightening means (37). A spring (29) is adapted, upon tightening of the coupling, to accumulate spring force urging the wedge surfaces of the members against each other. The coupling is suitable for interconnection of two or more elements (13, 14) in order to form a longitudinal guide for a boring machine.