Abstract: A captive screw formed of a lock screw, a cap-shaped knob, a spring member and a mounting barrel and mountable in a mounting through hole of a first panel frame and fastenable to a mounting screw hole of a second panel frame to detachably secure the second panel frame to the first panel frame is disclosed. The lock screw has a top protrusion raised from the top wall of the head thereof and a tool groove formed in the top protrusion. The cap-shaped knob is molded on the head of the lock screw by insert molding and defining an endless isolation groove on the top wall of the head of the lock screw around the periphery of the top protrusion that facilitates attachment of a hand tool to the top protrusion of the lock screw for enabling the lock screw to be driven by the user with the hand tool into the mounting screw hole of the second panel frame conveniently with less effort.

Abstract: A structure of plate positioning arrangement is disclosed. The structure of plate positioning arrangement comprises a shank extending at a bottom surface of a head of the positioning element, and a cap produced through a plastic injection molding process for covering and surrounding the edge of the head is for providing a receiving space below the head for fitting a fixing element. A through space is formed at a central region of the fixing element for fitting the shank of a positioning element, wherein the shank is fixed with a resilient element. Thus the cap is capability to allow the positioning element move in the same way within the through space of the fixing element.