Bolt-shaped light-metal threaded fastener e.g. screws has asymmetric thread flanks with pressure load-accommodating flank having esp. large flank angle

摘要

The fastener, e.g. screw, has an outer thread (2) with one pressure flank (3) to accommodate a pressure load, and a second opposite counter flank (4). The screw is of light metal alloy and the pressure flank angle (alpha 1) between the first flank and the normal (N), is larger than 30[deg], larger than 40[deg], and of the same size as, or larger than, the counter flank angle (alpha 2). The radius of curvature (R) on the thread root (5) is at least 10% of the thread pitch (P). A light metal alloy nut has an inner thread meshing with the screw.