How it works
The parts of a carabiner on a D-shaped locking one: spine, gate, hinge, nose, locking sleeve and strength markings. A second drawing opens the gate to show its latch and spring. This page names parts only.
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A loop with one side that opens
The spine is the long solid side. Across from it, the gate turns on the hinge and closes against the nose; a spring inside keeps it shut, and the latch at its free end catches in the nose. On a locking carabiner, a locking sleeve screws along the gate to hold it closed. The strength markings are stamped on the spine.
- Nose and latch meet when the gate shuts: the nose is on the frame, the latch is on the gate.
- The hinge is at the fixed end of the gate; the latch is at the free end.
Questions and answers
What is the gate on a carabiner?
The side that opens. It is a spring-loaded bar that turns on a hinge at one end and closes against the nose of the frame at the other.
What is the spine of a carabiner?
The long solid side across from the gate. A D-shaped carabiner is made so that most of the load falls on the spine, its strongest side.
What makes a carabiner a locking carabiner?
An extra part that holds the gate shut. On a screw-lock carabiner it is a threaded sleeve on the gate, turned by hand; auto-locking kinds have a sleeve that springs back by itself.
What do the markings on a carabiner mean?
They are strength ratings, usually on the spine, for three directions: lengthwise, sideways, and lengthwise with the gate open. Letters can also show the kind of use the carabiner was made for.