A SCREW HAVING A HEAD WITH CONCAVE UNDERSIDE

摘要

An integrally formed screw, such as a wood screw has a threaded cylindric stem and a head (9). At least a part (25) of the head (9) is shallowly convexly curved (25) and is provided with a screwdriver recess (-26). The head (9) has an 5 annular, shallowly concave underside (22) adapted to accommodate a relatively soft, polymeric washer (27).