Last updated
Clockwise from top left:
D-shaped wire gate
D-shaped straight gate
oval straight gate
pear-shaped auto locker
D-shaped screw locker.
Center is a standard carabiner rating. Assorted Biners.jpg
Clockwise from top left:
  • D-shaped wire gate
  • D-shaped straight gate
  • oval straight gate
  • pear-shaped auto locker
  • D-shaped screw locker.
Center is a standard carabiner rating.
Using a carabiner to connect to a rope Benutzung eines Karabiners.gif
Using a carabiner to connect to a rope

A carabiner or karabiner ( /ˌkærəˈbnər/ ), [1] often shortened to biner or to crab, colloquially known as a (climbing) clip, is a specialized type of shackle, a metal loop with a spring-loaded gate [2] used to quickly and reversibly connect components, most notably in safety-critical systems. The word comes from the German Karabiner , short for Karabinerhaken , meaning "carbine rifle hook" [3] used by a carbine rifleman, or carabinier, to attach his carbine to a belt or bandolier.



Carabiners are widely used in rope-intensive activities such as climbing, fall arrest systems, arboriculture, caving, sailing, hot-air ballooning, rope rescue, construction, industrial rope work, window cleaning, whitewater rescue, and acrobatics. They are predominantly made from both steel and aluminium. Those used in sports tend to be of a lighter weight than those used in commercial applications and rope rescue.

Often referred to as carabiner-style or as mini-carabiners, carabiner keyrings and other light-use clips of similar style and design have also become popular. Most are stamped with a "not for climbing" or similar warning due to a common lack of load-testing and safety standards in manufacturing.

While any metal link with a spring-loaded gate is technically a carabiner, the strict usage among the climbing community specifically refers only to devices manufactured and tested for load-bearing in safety-critical systems like rock and mountain climbing, typically rated to 20  kN or more.

Carabiners on hot-air balloons are used to connect the envelope to the basket and are rated at 2.5, 3, or 4 tonnes. [4]

Load-bearing screw-gate carabiners are used to connect the diver's umbilical to the surface supplied diver's harness. They are usually rated for a safe working load of 5 kN or more (equivalent to a weight in excess of approximately 500 kg). [5]



Carabiners come in four characteristic shapes:

  1. Oval: Symmetric. Most basic and utilitarian. Smooth regular curves are gentle on equipment and allow easy repositioning of loads. Their greatest disadvantage is that a load is shared equally on both the strong solid spine and the weaker gated axis. Often preferred type for racking biners due to their symmetric shape.
  2. D: Asymmetric shape transfers the majority of the load on to the spine, the carabiner's strongest axis.
  3. Offset-D: Variant of a D with a greater asymmetry, allowing for a wider gate opening.
  4. Pear/HMS: Wider and rounder shape at the top than offset-D's, and typically larger. Used for belaying with a munter hitch, and with some types of belay device. The largest HMS carabiners can also be used for rappelling with a munter hitch (the size is needed to accommodate the hitch with two strands of rope). These are usually the heaviest carabiners.

Locking mechanisms

Carabiners fall into three broad locking categories: non-locking, manual locking, and auto locking.


Non-locking carabiners (or snap-links) [6] have a sprung swinging gate that accepts a rope, webbing sling, or other hardware. Rock climbers frequently connect two non-locking carabiners with a short length of webbing to create a quickdraw (an extender).

Two gate types are common:

  1. Solid gate: The more traditional carabiner design, incorporating a solid metal gate with separate pin and spring mechanisms. Most modern carabiners feature a 'key-lock nose shape and gate opening, which is less prone to snagging than traditional notch and pin design. Most locking carabiners are based on the solid gate design.
  2. Wire gate: A single piece of bent spring-steel wire forms the gate. Wire gate carabiners are significantly lighter than solid gates, with roughly the same strength. Wire gates are less prone to icing up than solid gates, an advantage in Alpine mountaineering and ice climbing. The reduced gate mass makes their wire bales less prone to "gate flutter", a dangerous condition created when the carabiner suddenly impacts rock or other hard surfaces during a fall, and the gate opens momentarily due to momentum (and both lowers the breaking strength of the carabiner when open, and potentially allows the rope to escape). Simple wiregate designs feature a notch that can snag objects (similar to original solid gate designs), but newer designs feature a shroud or guide wires around the "hooked" part of the carabiner nose to prevent snagging.

Both solid and wire gate carabiners can be either "straight gate" or "bent gate". Bent-gate carabiners are easier to clip a rope into using only one hand, and so are often used for the rope-end carabiner of quickdraws and alpine draws used for lead climbing.


Locking carabiners have the same general shape as non-locking carabiners, but have an additional mechanism securing the gate to prevent unintentional opening during use. These mechanisms may be either threaded sleeves ("screw-lock"), spring-loaded sleeves ("twist-lock"), magnetic levers ("Magnetron"), other spring loaded unlocking levers or opposing double spring loaded gates ("twin-gate").

  • Screw-lock (or screw gate): Have a threaded sleeve over the gate which must be engaged and disengaged manually. They have fewer moving parts than spring-loaded mechanisms, are less prone to malfunctioning due to contamination or component fatigue, and are easier to employ one-handed. They, however, require more total effort and are more time-consuming than pull-lock, twist-lock or lever-lock.
Carabiner with multiple combined auto lock and quick release, useful in via ferrata and arborist work, where two lanyards and carabiners are used Sicherheitskarabiner.jpg
Carabiner with multiple combined auto lock and quick release, useful in via ferrata and arborist work, where two lanyards and carabiners are used
  • Twist-lock, push-lock, twist-and-push-lock: Have a security sleeve over the gate which must be manually rotated and/or pulled to disengage, but which springs automatically to locked position upon release. They offer the advantage of re-engaging without additional user input, but being spring-loaded are prone to both spring fatigue and their more complex mechanisms becoming balky from dirt, ice, or other contamination. They are also difficult to open one-handed and with gloves on, and sometimes jam, getting stuck after being tightened under load, and being very hard to undo once the load is removed.
  • Multiple-levers: Having at least two spring loaded levers that are each operated with one hand.
  • Magnetic: Have two small levers with embedded magnets on either side of the locking gate which must be pushed towards each other or pinched simultaneously to unlock. Upon release the levers pull shut and into the locked position against a small steel insert in the carabiner nose. With the gate open the magnets in the two levers repel each other so they do not lock or stick together, which might prevent the gate from closing properly. Advantages are very easy one-handed operation, re-engaging without additional user input and few mechanical parts that can fail.
  • Double-Gate: Have two opposed overlapping gates at the opening which prevent a rope or anchor from inadvertently passing through the gate in either direction. Gates may only be opened by pushing outwards from in between towards either direction. The carabiner can therefore be opened by splitting the gates with a fingertip, allowing easy one hand operation. The likelihood of a rope under tension to split the gates is therefore practically none. The lack of a rotating lock prevents a rolling knot, such as the Munter hitch, from unlocking the gate and passing through, giving a measure of inherent safety in use and reducing mechanical complexity.



United States

American National Standards Institute/American Society of Safety Engineers standard ANSI Z359.1-2007 Safety Requirement for Personal Fall Arrest Systems, Subsystems and Components, section (for snap hooks and carabiners) is a voluntary consensus standard. This standard requires that all connectors/ carabiners support a minimum breaking strength (MBS) of 5,000 lbf (22 kN) and feature an auto-locking gate mechanism which supports a minimum breaking strength (MBS) of 3,600 lbf (16 kN).


Hooks with a sprung, hinged gate, depicted on a horse's muzzle in the Codex Loffelholz folio 38v, about 1505 Codex Loeffelholz F 38v - detail - carabiner.png
Hooks with a sprung, hinged gate, depicted on a horse's muzzle in the Codex Löffelholz folio 38v, about 1505
Rather poor depiction of a carabiner attached to a shoulder belt, from Johann Jacob von Wallhausen's Kriegskunst zu Pferdt, 1616 Fotothek df tg 0000956 Kriegskunst ^ Pferd ^ Arkebussier ^ Gewehr ^ Rustung.jpg
Rather poor depiction of a carabiner attached to a shoulder belt, from Johann Jacob von Wallhausen's Kriegskunst zu Pferdt, 1616

The first known hooks that had a sprung, hinged gate where the spring kept it closed (characteristics expected of a carabiner) [8] were depicted by Nuremberg patrician Martin Löffelholz von Kolberg in about 1505 in the Codex Löffelholz, in the Holy Roman Empire. These then became the clip used to hold a cavalry carbine or arquebus, with the earliest known mention of them being in 1616 by Johann Jacob von Wallhausen, in the Holy Roman Empire. [9] They were widely used in many European countries during the 17th century, [8] and typically had a belt attachment and swivel joint, much like a modern luggage strap or handbag strap. The load bearing latch was added in the 1790s, [8] [10] for the British cavalry design. They were used for many other purposes during the 19th century, [8] such as for luggage straps, mining and connecting ropes. Some common designs first appeared during that time, including S-carabiners. Oval links, which had also appeared in 1485, also reappeared as carabiners. Screw gates and internal springs were developed. Prussian fire brigades began to use carabiners for connecting themselves to ladders in 1847, [11] [8] and this became the modern gourd-shaped design by 1868. [12] German and Austrian mountaineers started using them during the late 19th century, with a mention of their use from 1879, [13] and their continued use for climbing by climbers in Saxon Switzerland. [8] [14] The majority used gourd shaped carabiners which were created for mining or other utility purposes. [8] [14]

The common myth suggesting that they were invented, created, designed, made or developed by German climber Otto "Rambo" Herzog has no basis in fact. [15] [14] However, like many climbers before him, he did use them for some challenging climbs, and some new techniques. However, it is worth noting that he did not invent them, or develop any designs, and he was born long after other climbers were already using them. More designs were used by climbers during the 1920s, such as narrow pear shapes, mostly sold for general hardware. [8] [14] During the late 1920s and early 1930s, carabiners were being sold for climbing, [14] with oval designs being popular during the 1930s. Hardened steel carabiners appeared in the 1930s. Prototype aluminium carabiners, the first dedicated climbing carabiners, were made first by Pierre Allain during the 1930s, [16] [8] which were also the first offset D-shaped carabiner. Aluminium carabiners were first sold to the military in 1941, [17] which were the first commercial carabiners designed specifically for climbing. Slightly-offset D-shaped carabiners were sold in the late 1940s, which became the standard offset D-shape which is now the most common in the 1950s. [8]

Chouinard Equipment introduced the 22 kN aluminium carabiner in 1968, though this strength had already been far surpassed by steel carabiners. [8] Wiregate carabiners were first patented in 1969, and were sold for maritime use. [8] They were first sold for climbing in 1996. The popular keylock, which avoids snagging, was developed around 1984-1987. [8]

See also

Related Research Articles

<span class="mw-page-title-main">Butterfly loop</span> Knot used to form a fixed loop in the middle of a rope

The butterfly loop, also known as lineman's loop, butterfly knot, alpine butterfly knot, Swiss loop and lineman's rider, is a knot used to form a fixed loop in the middle of a rope. Tied in the bight, it can be made in a rope without access to either of the ends; this is a distinct advantage when working with long climbing ropes. The butterfly loop is an excellent mid-line rigging knot; it handles multi-directional loading well and has a symmetrical shape that makes it easy to inspect. In a climbing context it is also useful for traverse lines, some anchors, shortening rope slings, and for isolating damaged sections of rope.

<span class="mw-page-title-main">Quickdraw</span> Piece of climbing equipment used by rock and ice climbers

A quickdraw is a piece of climbing equipment used by rock and ice climbers to allow the climbing rope to run freely through protection such as bolt anchors or other traditional gear while leading.

<span class="mw-page-title-main">Glossary of climbing terms</span> For rock climbing and mountaineering

Glossary of climbing terms relates to rock climbing, mountaineering, and to ice climbing.

<span class="mw-page-title-main">Rock-climbing equipment</span> List of manmade gear

Rock-climbing equipment varies with the type of climbing undertaken. Bouldering needs the least equipment outside of shoes and chalk and optional crash pads. Sport climbing adds ropes, harnesses, belay devices, and quickdraws to clip into pre-drilled bolts. Traditional climbing adds the need for carrying a "rack" of temporary passive and active protection devices. Multi-pitch climbing adds devices to assist in ascending and descending fixed ropes. And finally aid climbing uses unique equipment.

<span class="mw-page-title-main">Abseiling</span> Rope-controlled descent

Abseiling, also known as rappelling, is the controlled descent of a steep slope, such as a rock face, by moving down a rope. When abseiling, the person descending controls his own movement down the rope, in contrast to lowering off, in which the rope attached to the person descending is paid out by his belayer.

Self-locking devices are devices intended to arrest the fall of solo climbers who climb without partners. This device is used for rope solo climbing, for "ground-up climbing", and for "top rope solo climbing". To date, several types of self-locking devices have evolved.

<span class="mw-page-title-main">Belaying</span> Rock climbing safety technique using ropes

Belaying is a variety of techniques climbers use to create friction within a climbing system, particularly on a climbing rope, so that a falling climber does not fall very far. A climbing partner typically applies tension at the other end of the rope whenever the climber is not moving, and removes the tension from the rope whenever the climber needs more rope to continue climbing.

<span class="mw-page-title-main">Munter hitch</span> Adjustable knot used control friction in a belay system

The Munter hitch, also known as the Italian hitch, mezzo barcaiolo or the crossing hitch, is a simple adjustable knot, commonly used by climbers, cavers, and rescuers to control friction in a life-lining or belay system. To climbers, this hitch is also known as HMS, the abbreviation for the German term Halbmastwurfsicherung, meaning half clove hitch belay. This technique can be used with a special "pear-shaped" HMS locking carabiner, or any locking carabiner wide enough to take two turns of the rope.

Kernmantle rope is rope constructed with its interior core protected by a woven exterior sheath designed to optimize strength, durability, and flexibility. The core fibers provide the tensile strength of the rope, while the sheath protects the core from abrasion during use. This is the only construction of rope that is considered to be life safety rope by most fire and rescue services.

<span class="mw-page-title-main">Bachmann knot</span> Type of knot

The Bachmann hitch is a friction hitch, named after the Austrian alpinist Franz Bachmann. It is useful when the friction hitch needs to be reset quickly or often or made to be self-tending as in crevasse and self-rescue.

<span class="mw-page-title-main">Offset overhand bend</span> Knot used to join two ropes together

The offset overhand bend is a knot used to join two ropes together end-to-end. It is formed by holding two rope ends next to each other and tying an overhand knot in them as if they were a single line. Due to its common use in several fields, this bend has become known by many names, such as thumb knot, openhand knot, one-sided overhand knot or flat overhand bend (FOB), though the terms "one-sided" and "flat" are considered incorrect.

<span class="mw-page-title-main">Ascender (climbing)</span> Devices used for ascending, braking, or protection in climbing

An ascender is a device used for directly ascending a rope, or for facilitating protection with a fixed rope when climbing on very steep mountain terrain. A form introduced in the 1950s became so popular it begat the term "Jumar" for the device, and the verb "to jumar" to describe its use in ascending.

<span class="mw-page-title-main">Prusik knot</span> Type of knot

A Prusik is a friction hitch or knot used to attach a loop of cord around a rope, applied in climbing, canyoneering, mountaineering, caving, rope rescue, ziplining, and by arborists. The term Prusik is a name for both the loops of cord used to tie the hitch and the hitch itself, and the verb is "to prusik" or "prusiking". More casually, the term is used for any friction hitch or device that can grab a rope. Due to the pronunciation, the word is often misspelled Prussik, Prussick, or Prussic.

In rock climbing, an anchor can be any device or method for attaching a climber, rope, or load to a climbing surface—typically rock, ice, steep dirt, or a building—either permanently or temporarily. The intention of an anchor is case-specific but is usually for fall protection, primarily fall arrest and fall restraint. Climbing anchors are also used for hoisting, holding static loads, or redirecting a rope.

<span class="mw-page-title-main">Climbing rope</span> Rope used to secure climbers

A climbing rope is a rope that is used in climbing. It is a critical part of an extensive chain of protective equipment used by climbers to help prevent potentially fatal fall-related accidents.

<span class="mw-page-title-main">Dynamic rope</span> Rope designed to stretch under load

A dynamic rope is a specially constructed, somewhat elastic rope used primarily in rock climbing, ice climbing, and mountaineering. This elasticity, or stretch, is the property that makes the rope dynamic—in contrast to a static rope that has only slight elongation under load. Greater elasticity allows a dynamic rope to more slowly absorb the energy of a sudden load, such from arresting a climber's fall, by reducing the peak force on the rope and thus the probability of the rope's catastrophic failure. A kernmantle rope is the most common type of dynamic rope now used. Since 1945, nylon has, because of its superior durability and strength, replaced all natural materials in climbing rope.

<span class="mw-page-title-main">Belay device</span> Mechanical piece of climbing equipment

A belay device is a mechanical piece of climbing equipment used to control a rope during belaying. It is designed to improve belay safety for the climber by allowing the belayer to manage their duties with minimal physical effort. With the right belay device, a small, weak climber can easily arrest the fall of a much heavier partner. Belay devices act as a friction brake, so that when a climber falls with any slack in the rope, the fall is brought to a stop.

<span class="mw-page-title-main">Garda hitch</span> Type of climbing knot

The Garda Hitch, also known as the Alpine Clutch, is a type of climbing knot that can only be moved in one direction. It is often used in climbing and mountaineering, such as in pulley systems to haul loads up a cliff. However, the Garda Hitch has some drawbacks, including being difficult to release under load, difficult to inspect, and adding significant friction to a pulley system. It can be challenging to determine which direction the rope will move freely and which direction it will lock just by looking at it. To tie a Garda Hitch, you need two similar carabiners, and it works best with two identical oval carabiners. While "D" carabiners can also be used, there is a risk of them unclipping.

<span class="mw-page-title-main">Radium release hitch</span>

A radium release hitch is a load-releasing hitch using 3:1 mechanical advantage which is used in a two-rope technical rescue system. The Radium Release Hitch allows a load to be transferred from one rope to another and is commonly rigged into the belay line prior to the operation of a two-rope technical rescue system.


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  17. . Retrieved 2024-01-17.{{cite web}}: Missing or empty |title= (help)