Shackles
Four-Part Shackles
Four-part shackles are designed for added safety and are often used in overhead or long-term rigging applications. These shackles include a nut, bolt-type pin, and a safety keeper or cotter pin that prevents the nut from backing off. This added feature helps ensure that the pin stays securely in place during lifting, movement, or exposure to vibration.
The safety keeper or cotter pin must match the size of the hole in the pin. It should be long enough and thick enough to stay securely in place, without room to move or fall out. If the cotter pin is missing, too short, or too thin, the entire shackle assembly should not be used until the correct part is installed.
Never assemble or use a four-part shackle with only the safety pin in place. The nut must always be installed and fully tightened before inserting the safety pin. This ensures the load is properly supported and the pin will not loosen during use.
Before loading the shackle, always check that the nut is in position and hand-tightened. Only after the nut is secure should the safety pin be installed. Skipping this step can result in a loose connection that may fail under load.
Four-part shackles are best suited for permanent or semi-permanent overhead installations where the connection may be exposed to vibration, movement, or impact. These shackles must be inspected weekly to make sure the nut and safety pin remain in place and the shackle has not been bent, damaged, or affected by nearby equipment. If damage is found, the shackle must be removed from service immediately.
Knowledge Check Choose the best answer for the question.
7-7. Before hoisting a load overhead, what is the final part installed on the four-part shackle?
You forgot to answer the question!