Which type of connector allows for secure closure by screwing a nut onto threads?

The screw link is designed to provide a secure closure by having a threaded section that allows a nut to be screwed onto it. This threading mechanism ensures that the connection is not only tight but also resistant to accidental opening or disconnection, making it particularly useful in scenarios where safety and reliability are critical, such as in confined space rescue operations.

Using a screw link is especially important when dealing with heavy loads or when working in environments where a sudden force might dislodge a simpler connector. The ability to screw the nut down creates a more robust and secure connection that can safeguard against potential hazards during rescues.

In contrast, snap hooks and carabiners are versatile connectors that typically rely on a gate mechanism or spring action to open and close, providing quick attachment and detachment but lacking the same level of security against unintentional release. Wire clips, while useful in certain applications, do not offer the same level of robustness in securing connections as a screw link. Therefore, in situations where utmost security is necessary, the screw link is the preferred choice.