​Carabiner Safety: How an Open Gate Reduces Strength by 70%

A carabiner or snap hook is only as strong as its closure. A fully closed and locked carabiner is critically important for maintaining maximum strength and load-bearing capabilities. When the carabiner gate is open even slightly, the strength can be drastically reduced, often by up to 70%.
This happens because a closed gate preserves the structural integrity of the carabiner, distributing forces as tension along its spine. In contrast, an open gate carabiner introduces bending forces and stress concentrations, which can cause premature failure. For anyone concerned with climbing safety, fall protection, or industrial rigging, this distinction is lifesaving.


Carabiner Strength: Open Gate vs. Closed Gate
The strength of a climbing carabiner is usually measured in kilo-Newtons (kN). For example:

• Closed gate strength: A standard carabiner may be rated at 32 kN when the gate is fully closed.
• Open gate strength: That same carabiner may drop to just 10 kN with the gate open.

That’s a 70% reduction in strength, making the carabiner highly vulnerable to deformation and failure. Instead of carrying tension along the spine, the load creates bending forces, which carabiners are not designed to handle.
👉 This is why open gate loading is considered one of the most dangerous situations in both climbing gear and safety equipment.

The Importance of Full Closure and Locking Carabiners
While most carabiners are rated for closed-gate strength, many also feature locking mechanisms such as screw gates or auto-locks.

• A locking carabiner ensures that the gate stays shut during use.
• Locking systems prevent accidental gate opening, a common cause of strength loss.
• For climbers, workers at height, and rescue professionals, locking carabiners offer essential peace of mind.

Even though the strength rating does not increase with locking, the safety factor does because the risk of gate flutter or accidental opening is eliminated.


Common Reasons Carabiners Don’t Fully Close
Several issues can prevent a carabiner gate from closing or locking fully. These include:

• Hooking in clothing: In fall protection, attaching an SRL or lanyard to the dorsal D-ring may cause the carabiner to snag on clothing, leaving the gate partially open.
• Debris and dirt: Sand, mud, or grit inside the hinge or lock can stop smooth closure.
• Damage or deformation: Dropped or bent carabiners may not align properly, preventing closure.
• Improper loading or cross-loading: If the carabiner is clipped incorrectly, the gate may press against an anchor point and stay open.
• Obstructions in the gate path: Ropes, webbing, or slings can become caught, keeping the gate from closing fully.
• Worn or faulty locking mechanisms: Over time, the sleeve or auto-lock system can wear out or fail.
• Incorrect usage: Sometimes users forget to twist a screw lock or engage an auto-lock fully.

👉 Regular inspection and cleaning of carabiners is essential for maintaining climbing gear safety and work-at-height compliance.


Conclusion: Carabiner Safety Is Non-Negotiable
A carabiner with an open gate can lose up to 70–76% of its rated strength, making it unsafe for load-bearing use. Whether in climbing, fall protection, or industrial rigging, always ensure your carabiner is fully closed and locked before trusting it.
Best practices for carabiner safety:

• Inspect carabiners regularly for dirt, damage, or wear.
• Use locking carabiners in high-risk situations.
• Confirm the gate is fully shut and locked before loading.

Carabiners are small but critical pieces of equipment. Treating carabiner safety as a priority is more than a formality; it’s a life-saving requirement.

This blog is a participant in Amazon’s Associate Program.