Carabiner Strength Ratings, Demystified (No Math Degree Required)

kN in one minute

• kN = kilonewtons. 1 kN ≈ 224.81 lbf (pounds-force).

• So 25 kN ≈ 5,620 lbf. 12 kN ≈ 2,698 lbf. Big numbers—but context matters.

The three numbers that matter

• Major-axis strength (gate closed): the headline rating on the spine.

• Minor-axis strength: when cross-loaded. Usually much lower.

• Open-gate strength: also lower; dynamic loads + open gate = trouble.

Why a high major-axis number isn’t a free pass

Real use is messy: ropes shift, devices twist, and people get tired. That’s why lockers exist and why technique matters more than spec sheet flexing.

Let's have an example:

• Auto-Lock D, 25kN (major), with typical minor/open-gate numbers in the single digits; it’s UIAA/EN certified and built for high-consequence links.

• Wire-Gate D, 12kN: stout for gear, camp, EDC, racking. Not for life support.

Practical takeaways

• Load along the spine; avoid cross-loading.

• Keep the gate closed; with lockers, keep it locked.

• Respect open-gate and minor-axis ratings—they’re there for a reason.

• Replace after major shock, visible deformation, cracks, or deep grooves.