Carabiner - Definition and Overview

A carabiner or karabiner (colloquially, crab, krab, or 'biner) is a gated connector: a metal loop with a usually sprung gate designed as a connector that can quickly and reversibly join together components in safety-critical systems; for example, a common use is to attach a rope to a fixed anchor.

Carabiners are widely used in sports requiring ropework, such climbing, caving, canyoning, and sailing, and in industrial rope access work, such as construction or window cleaning.

Carabiners used in climbing tend to be lighter and faster to use than carabiners used in industry. For example, some carabiners used in industry do not have a sprung swinging gate but have a screw shut gate that generally can only be opened and closed using a special tool; using such a carabiner when rock climbing would be unacceptable because carabiners must be capable of operation quickly and with one hand.

Note that, in German, "Karabiner" means "carbine" (a short rifle). The German term for a Carabiner is "Karabinerhaken".

Mountaineering

D-shaped carabiner with wire gate, used in mountaineering.

When sold for use in climbing in Europe carabiners must conform to standard EN 12275:1998 "Mountaineering equipment - Connectors - Safety requirements and test methods" which governs testing protocols, rated strengths, and markings.

There are broadly two sorts of carabiner used in climbing, with some subdivision within those: snapgate carabiners and screwgate carabiners. Snapgate carabiners are the simplest, there is a sprung swinging gate that can be opened to insert or remove a rope. The gate will snap shut under pressure of the spring. Screwgate carabiners are generally the same as snapgate carabiners, but have an additional sleeve around the gate on a screw thread. The sleeve can be rotated along the gate and when it is at one end of the gate the gate cannot be opened (except by unscrewing the sleeve and moving it to the other end of the gate). This provides security against the carabiner opening accidentally, for example if struck against the rock or if caught in a loop of rope.