Pintle exotic metal alloys. For World War II aircraft with sideways-retracting main gear units, carefully set-up "pintle angles" for such axes of rotation during retraction and extension allowed the maingear struts to be raked forward while fully extended for touchdown and better ground handling, while permitting retraction into rearwards-angled landing gear wells in their wings to usually clear the forward wing spar for stowing while in flight. Pintle A pintle is a pin or bolt, usually inserted into a gudgeon, which is used as part of a pivot or hinge. Other applications include pintle and lunette ring for towing, and pintle
Hinge teeth these function as hinge teeth. This arrangement is characteristic of the Pandoridae, the jingle shells Anomiidae, and Dimyidae. The "schizodont" hinge has reverse "V" shaped scissurate teeth, and often an elongated lateral tooth. This arrangement is found in most Unionidae freshwater mussels. The "pachyodont" hinge has large obscure tubercules with corresponding pits on the opposite valve. This arrangement is characteristic of the Chamidae, the jewel boxes. The "heterodont" hinge has two to three wedge-shaped cardinal teeth set in the center near the umbones, and generally also has elongated lateral teeth on the anterior and posterior margins (on one or both