A carabiner or karabiner (colloquially: "crab", "D ring", "krab", or "
'biner") is a metal loop with a sprung or screwed gate. [cite web |url=http://www.mountaindays.net/content/articles/dictionary.php#karabiner |title=Climbing Dictionary & Glossary |publisher=MountainDays.net |accessdate=2006-12-05] The loop part opposite the gate is referred to as the spine. It can quickly and reversibly connect components in safety-critical systems. The word comes from "Karabinerhaken", meaning "hook for a carbine" in German. [cite web |url=http://www.bartleby.com/61/53/C0095300.html |title=The American Heritage Dictionary: carabiner |publisher=Bartleby |accessdate=2006-12-05]
According to Fergus Fleming's book on the beginning of alpinism, "Killing Dragons: The conquest of the Alps", the British climbers derided aids like carabiners,
ice picks and crampons for some time, leaving their development to Italian, French and other alpinists. Therefore, the term "carabiner" was never properly translated into an English counterpart.]
Carabiners are widely used in sports requiring ropework, such as
climbing, slacklining, caving(" Single Rope Technique"), canyoning, and sailing, and in industrial rope accesswork, such as construction or window cleaning.
Carabiners used in sports tend to be lighter than carabiners used in industry. For recreational climbing, almost all carabiners are made from
7075 aluminumand are treated to a T6 temper (solution treated and then artificially aged).Fact|date=May 2008 For rope rescues and industrial uses, where the weight of the carabiner is not an important factor and larger working loads are encountered, steel carabiners are commonly used. Some carabiners used in industry do not have a sprung swinging gate but have a screw shut gate that generally can be opened and closed only using a special tool.
Carabiners have also found a place in popular usage as key holders, and as water-bottle holders for hikers.
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. A strength of around 20 kN with the gate shut is considered a standard strength for most climbing applications, although requirements vary depending on the activity.Carabiners are also marked on the side with single letters showing their intended area of use, for example, K (
via ferrata), B (base), and H (for belaying with an Italian / Munter hitch).
When used for access in commercial and industrial environments within Europe carabiners must comply with EN 362:2004 "Personal protective equipment against falls from a height. Connectors" As climbing and access in these environments use shock prevention devices the minimum strength of a carabiner to EN362:2004 is lower than that of a carabiner compliant with EN 12275:1998 at around 15 kN. Carabiners complying with both EN 12275:1998 and EN 362:2004 are available.
There are two broad categories of carabiner used in climbing—nonlocking and locking—with some subdivision within those categories.
Nonlocking carabiners have a sprung swinging gate that can be opened to insert or remove a rope, webbing sling, or other climbing hardware. The gate snaps shut under the spring's pressure. Mountaineers also frequently use a short sling to connect two nonlocking carabiners to each other, creating a
The gate used depends on the use and preference of the user. The following are the different types of gates for nonlocking carabiners:
;Straight gate: These gates are most common and are the cheapest and strongest.
;Bent gate: Without sacrificing strength, these gates allow things to be clipped in more easily than with straight gates. These can also unclip more easily, so are only used in specific situations, such as connecting ropes to quickdraws.
;Wire gate: These gates are made of wire and have strength comparable to a normal carabiner. They are the lightest type of carabiner, which allows the climber to carry more before being loaded down. They are also less prone to icing up than solid gate designs and the reduced mass of the gate makes the carabiner less prone to the problem known as 'gate flutter,' a dangerous condition in which the gate opens as a result of the momentum of a fall.
Locking carabiners have the same general shape as nonlocking carabiners, but have an additional sleeve around the gate. The sleeve can be released along the gate and, when it is at one end of the gate, cannot be opened (except by releasing 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 a rock or if caught in a loop of rope. The sleeve can be either auto-locking or a twist-lock.
;Auto-locking gate: These gates allow for quick locking and also prevent the user from forgetting to lock the carabiner. The disadvantages are that the spring can wear out or break, preventing it from locking, and it is harder to use with one hand because you have to hold the gate lock to keep it from locking again.
;Twist/screw lock gates: These gates are similar to a nut on a bolt. They are sleeves that twist up and down and must be done manually.
There are several different shapes of carabiners.
;Oval: These are the cheapest and most basic because they are symmetric and can be used for anything. The biggest disadvantage is that the load is equally shared with the gate side, which is the weakest part of the carabiner. The advantage to the oval shape is that its smooth radius allows for smooth repositioning of the type of shifting loads produced in
;D: These are in the shape of a D and move most of the force onto the spine of the carabiner which is the strongest part. This makes the carabiner stronger, but in turn they are more expensive.
;Offset-D: These are similar to the D carabiners, except the gate opening end is bigger than the hinge side. This allows the gate to open more and makes it easier to clip things into the carabiner.
;Pear/HMS: Pear shaped carabiners are oversized, offset-D carabiners. They allow more to be hooked onto the carabiner, and are also used for
Munter hitchbelays. They are the most expensive and heaviest carabiner. These are generally known to climbers as HMS Carabiners.
Carabiners are also useful in everyday life, for securing water bottles to belts, or pen knives etc. Cheap and colorful carabiners that vaguely resemble mountaineering carabiners, but are generally thinner, smaller and made of a lower grade metal have become quite popular as keyrings or in other applications as a universal connector. They have an extremely simplified latching mechanism, without a pin to allow the gate to carry a load. Such novelty carabiners are typically marked with an explicit liability warning, e.g. "Not for climbing", as well as a low maximum load, e.g. "Not to exceed 20 lbs."
Glossary of climbing terms
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