A body having a thin region in substantially a half lower portion and a head joined to the body by a neck. When the element is blanked out of a metal sheet, an excess amount of metal produced by pressing the substantially half lower portion of the body flows from the body into the metal sheet positioned on an opposite side of the neck and a metal flow is produced into laterally spaced ends of the neck. The head has relatively thick laterally spaced ends and the head and the body have respective thicknesses equal to or smaller than the thickness of the head. The laterally spaced side end regions of the body have a thickness smaller than a thickness of the lower region of the neck in the substantially half upper portion of the body.