Which shackle should not be used for overhead lifting?

A screw pin shackle should generally not be used for overhead lifting, especially in critical applications, because the pin can loosen and unscrew during use, leading to potential failure. Instead, a safety shackle, which has a locking mechanism to prevent accidental opening, is recommended for such tasks. Additionally, bow shackles are often preferred for overhead lifting due to their design, which provides greater load-bearing capacity and stability. Always ensure that any shackle used is properly rated for the load and application.