Hinge-Line Clearance—Toys having a gap or clearance
along the hinge line between a stationary portion and a
moveable portion that weighs more than 1⁄2 lb (0.2 kg) shall be
so constructed that, if the accessible gap at the hinge line will
admit a 3⁄16-in. (5-mm) diameter rod, it will also admit a 1⁄2-in.
(13-mm) diameter rod at all positions of the hinge.