A knuckle joint is a type of pin joint used to join two components that are loaded in tension. One component has a fork with a hole passing through both sides, forming a double eye, while the other component has a single eye.
The single eye is inserted between the double eyes so that all three holes are concentric and a pin is used to secure the components.
Knuckle joints are often used to connect rods subjected to tension in structures such as roof ties, bridges, and cranes. The links of a chain are also considered a series of knuckle joints.
