Knuckle joint
Also called: rule joint, finger hinge joint
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A knuckle joint is a furniture joint for allowing a table part to move, such as a swing leg.
Furniture use
The documented uses include swing legs on card and occasional tables, and a traditional knuckle joint in a solid walnut table. These examples establish the furniture setting, but do not supply one universal cutting pattern or hinge size.
Do not confuse the names
A rule joint, a table-flap joint, is another furniture form described alongside this subject. Its hinge is hidden from the front when the flap is raised or lowered, and a rounded edge on an overhanging cap can prevent binding as the flap opens.
Careful fitting
Rule-joint work depends on careful measurement and fitting. Apply the same discipline to a moving knuckle joint: check the movement before fixing the parts, and make sure the meeting edges do not foul one another.