The ornamental design for a singlesidedfastener, as shown and described.
FIG. 1 is an isometric view of an ornamental design for a single sided fastener, according to the present disclosure.
FIG. 2 is a front view of the single sided fastener of FIG. 1. The single sided fastener has rotational symmetry. Therefore the back view and the side views mirror the front view shown in FIG. 2; and,
FIG. 3 is a top view of the single sided fastener of FIG. 1.
The solid lines in FIGS. 1-3 illustrate a single sided fastener according to the present disclosure. The broken lines illustrate portions of the single sided fastener and form no part of the claimed design.