Abstract: A fence is assembled from tubular posts and open-ended tubular cross-pieces the ends of which are slidably supported on the posts and selectively secured in one of several discrete positions, for example by engaging transverse slots in the lower face of the cross-pieces on tabs in apertures in the posts. In another arrangement, flaps in the posts are folded in to form apertures slidably receiving ends of the cross-pieces, which are secured by selectively engaging pins in aligned holes in the flaps and cross-pieces. The fence may include a rectangular gate frame formed by folding a suitably cut-out tubular piece.