Abstract: A dual articulated spline windshield wiper assembly for use in a conventional windshield wiper yoke and claw assembly comprises a relative high durometer plastic upper spline and a high durometer plastic lower spline that are coupled for relative rotation about a first axis, the lower spline having a low durometer wiping blade mounted thereon for limited rotation relative to the lower spline about a second axis parallel to said first axis.

Abstract: An externally threaded male fastener has a right circular cylinder at one end that is slidably engageable with the internal threads of a female element, a pair diametrically opposed circumferentially truncated approach thread portions between the right circular cylinder and its conventional threads, and a pair of diametrically opposed unthreaded portions between the approach thread portions that preclude cross-threading with an internally threaded female element.