Abstract: Disclosed is an attachment system for detachably coupling a female tube end and a male tube end to each other to form foundation piles. The system includes corresponding cylindrical sleeve holes in tube sleeves of the tube ends; a coupling element which is fittable in the sleeve holes and rotatable through an angle therein; a blocking pin on the coupling element or on one of the sleeve holes; and a blocking slot in one of the sleeve holes or in the base body, so that the blocking pin engages in the blocking slot upon rotation of the coupling element in the sleeve holes. Additionally, one of the sleeve holes and the base body can be provided with corresponding sleeve slots in order to form a fitting hole together to fit a blocking element therein, in order to prevent rotation of the coupling element in the sleeve holes.