A fastener comprises a threaded shank extending along an axis between top and bottom ends and a semi spherical body affixed at the top end of the threaded shank. The fastener further comprises a head having a receptacle adapted to closely surround the semi-spherical body, the head being pivotable about the semi spherical body and rotatably fixed relative to the semi spherical body about the axis of the threaded shank and a drive disposed on the head adapted to receive a tool for rotating the head and the threaded shank about the axis of the threaded shank.