Multiple use screw with tapered threads

摘要

A threaded screw has a first segment adjacent the screw head (10) with nontapered sides for engaging metal automotive fastener clip nuts (30) and a second segment with tapered sides for engaging plastic bosses (24). The second segment is adjacent the first segment but distant from the screw head (10). A single set of threads (36) is used for both the metal clip nut (30) and the plastic boss (24). The threads (36) have a helical pitch angle (P) of about nine degrees and form a flank angle ( beta ) of about thirty degrees relative to a horizontal axis (20) of the screw. The screw taper matches the taper of the boss opening (22) to promote even stress distribution.