The invention relates to the formation of an article which is wholly formed with a thread formation or includes a portion which is threaded. The threaded portion is formed by winding a wire in a helical path around a series of spaced support members. The wire forms the thread and also forms a slot in a helical path between adjacent portions of the wound wire. A suitable threaded member can then be introduced to the article and selective rotation causes relative movement of the threaded member along the threaded portion. The article can be used as a filter medium, a securing means and the like and the wire used is typically triangular in cross section and known as wedge wire.