The invention relates to a method for the unreleasable fastening of at least one component to a basic component with the aid of a bolt projecting through a bore in the component or components, first the bolt being welded electrically with one end face on the surface of the basic component and subsequently being deformed plastically. So that components consisting of any desired materials can be used, it is proposed, according to the invention, that the shank of the bolt, which has a head, be upset, until the underside of the head lies in regions on the surface of the component. Furthermore, an unreleasable connection of one or more components to a basic component is proposed.