Fastening method and apparatus

A fastener (10) includes a clamp arm (26)which is connected with a base (24). The clamp arm (26) cooperates with the base (24) to form an entrance (80) into which an article (14) extends. A first locking tab (40) extends from the base (24) into a first opening (64) in the article (14). A second locking tab (120) extends from the clamp arm (26) into a second opening (142) in the article. When a withdrawal force is applied to the fastener, an arcuate portion (116) of an inner side surface (108) of the clamp arm (26) moves from a position spaced from an outer side surface (164) of the article (14) to a position in which the arcuate portion of the inner side surface of the clamp arm is disposed in abutting engagement with the outer side surface of the article.