Do Carabiners Weaken Over Time?

This is a critical question for anyone whose safety depends on this fundamental piece of gear, from climbers and mountaineers to arborists and rescue professionals. The straightforward answer is: carabiners do not inherently weaken from age alone if stored properly, but they absolutely can degrade and weaken due to factors related to use, care, and environmental exposure over time. Their lifespan is not defined by a calendar but by a history of stress, wear, and damage.

The Role of Materials and Design

Modern climbing carabiners are engineered from high-strength aluminum alloys (like 7075-T6) or steel. These materials, when untouched and stored in a cool, dry place, are highly stable. You could theoretically store a new carabiner in ideal conditions for decades, and its molecular structure and strength rating would remain largely intact. The weakness rarely comes from the metal itself "aging," but from what happens to it during its service life.

Key Factors That Cause Real Weakening Over Time

1. Metal Fatigue: This is a primary concern. While a carabiner is designed to withstand thousands of loading cycles, repeated stress—especially if it is dropped, shock-loaded, or used in high-friction systems like a top-rope anchor—can cause microscopic cracks to initiate and grow. This fatigue is cumulative and can eventually lead to failure under load.
2. Surface Damage and Wear: This is the most visible culprit. Deep grooves cut by ropes or cables concentrate stress, dramatically reducing breaking strength. Cracks, even hairline, are immediate retirement flags. Dents and sharp burrs from impacts with rock or tools also compromise structural integrity.
3. Corrosion: Exposure to certain chemicals, saltwater (sea cliff climbing), or even persistent moisture can lead to corrosion. For aluminum, this often appears as white, powdery oxidation, which is generally superficial. However, pitting corrosion—small, deep holes—is a serious weakening factor. More insidious is stress corrosion cracking, which can occur without obvious visible signs.
4. Gate and Mechanism Wear: The moving parts are vulnerable. A gate that doesn't snap shut firmly, has excessive play, or whose locking mechanism (screw or auto) is gritty or failing, indicates wear. A malfunctioning gate can drastically reduce the carabiner's effective strength.

The Critical Importance of Inspection, Not Assumption

Therefore, the question is not "How old is it?" but "What has it been through?" and "What does my inspection reveal?" A five-year-old carabiner used weekly in a gritty environment may be far more compromised than a ten-year-old carabiner used only a few times and stored perfectly.

Your inspection ritual should be meticulous:

• Visually scan every millimeter for cracks, grooves, and corrosion.
• Feel for rough spots, burrs, and pitting.
• Test the gate action and locking mechanism for smooth, positive function.

When to Retire a Carabiner

Retire a carabiner immediately if you find any crack, deep groove, significant corrosion, or gate malfunction. Also retire any piece that has endured a severe fall, a major impact (like being struck by rockfall), or exposure to unknown chemicals. Manufacturers often suggest a general guideline of up to 10 years for recreational use with impeccable care, but this is a conservative benchmark, not a guarantee.

Conclusion: A History, Not an Expiration Date

Carabiners weaken not from the passage of time, but from the history written upon them through use. There is no automatic expiration date. Your ultimate safety tools are proactive care (keeping them clean and dry), conservative use (avoiding abusive loads), and most importantly, a rigorous and routine inspection practice. When the history of wear becomes visible or tangible, it is time for the carabiner to be honorably retired from life-support roles. In doubt, always err on the side of caution and replace it.