Carabiners on rock

There are three essential pieces of gear that modern rock climbing would be impossible without: harness, rope, and of course your rock climbing carabiner.

It is amazing that these simple items have evolved over the past few decades to enable people to scale thousands of feet with minimal risk, to save lives, and to push the boundaries of possibility. 

Especially something often smaller than the size of your hand. 

What is a “carabiner”?

A carabiner is an oval-shaped ring, generally made of metal or plastic, that has a gate. The gate is a spring-hinged segment of the ring that opens and closes, therefore allowing things to be clipped into/attached to the ring.

You may have seen carabiners before at the hardware store or supermarket. The ones sold at these places are not for climbing (and if you look closely, might even be inscribed with the words “not for climbing”) but for everyday purposes like holding your keys or organization hacks you find on Pinterest. Such carabiners are usually made of plastic or cheap metal, because they don’t need to be super sturdy to get the job done.  

Carabiners as a keychain

Carabiners intended for climbing use, on the other hand, are not your average “clippy oval thingy”. They are generally made of steel and aluminum and have to go through very rigorous manufacturing and testing processes. This is because they have to hold weight and withstand a certain amount of force without breaking. 

Carabiners for Rope Access and Industrial work are even more hardcore. They are often heavy duty, made of steel, and subjected to different degrees of testing and certification than climbing carabiners. Folks looking to purchase carabiners for use in this manner should not get climbing carabiners, but instead, find ones rated specifically for the job they need to get done.

If you fall into this category and are still questioning whether you can get by with non-industry grade stuff, read this.

Likewise, if you are rock climbing, do not use carabiners made for Rope Access and Industrial work…

The Basic Anatomy of a Rock Climbing Carabiner

Climbing carabiners also come in a wide variety of styles and shapes, each type serving a particular need.

To understand the differences between climbing carabiners and make an educated decision on which ones are best for you, it’s a good idea to learn some basic anatomy and vocabulary:

The Basic Anatomy of a Rock Climbing Carabiner

The gate is the only moving part of the whole thing. It opens and closes – and when it closes, it should do so by itself due to its being spring-loaded  (immediately snapping back into place). If the gate does not snap back into a fully closed position by itself, then the carabiner is no longer in good condition. 

Gates come in three primary styles: wire, standard, and locking.  

Wire gates look like a wire wrapped in a loop. This type of gate is used to reduce weight, as it has less metal and more empty space while still maintaining the same function of a standard gate.

Standard gates, like the one on the carabiner pictured above, consist of a solid bar of metal. These weigh more than wire gates, but are purportedly sturdier. 

Locking gates look similar to a standard gate, but with a bulky cylinder around it that functions as the lock and  guarantees the gate stays closed. The lock can be manual, which means you have to actively spin the cylinder on its threads until it is super tight and slightly covers the carabiner’s nose. It can also be a “twist lock”: these only open when slightly rotated to face a certain way, and automatically snap into a “locked” position when released. Occasionally you might run into a magnetic style lock. This uses two magnets on opposing sides of the gate to keep it shut, and can be opened by pinching down on both at once while pulling the gate back. 

Gates can also be straight or bent. Straight gates extend from end to end in a straight line, and are best for clipping into bolts. Bent gates are slightly curved and work better for clipping into ropes, as your finger/thumb is less likely to slip off. 

The nose is where the top of the gate reattaches to the carabiner when closed. Noses are designed differently to accommodate certain types of gates. 

A keylock nose has a smooth arch that curls back towards the inside of the carabiner, and is used for standard gates. Standard gates have a small notch in the top, which the keylock nose piece slips into. Keylock noses are ideal because they generally don’t snag. 

Non-keylock noses curl back into a hook, and are used on wire-gate carabiners. This is so the top of the gate’s wire loop can latch over and into the hook. 

The rope basket is the large, arched top of the carabiner, curved to help reduce wear on the rope by having it run through only one spot (not allowing it the ability to slide around side-to-side). 

The runner end refers to the smaller-arched bottom side of the carabiner. Depending on the carabiner’s purpose, the runner’s end can serve many different functions (e.g. the connection point for a piece of webbing). 

The spine is the solid, long side of the carabiner opposite of the gate. It endures most of the force applied to the carabiner, and so it is the strongest part. All climbing carabiners should have their strength rating, followed by their certification, engraved onto the spine. 

Rock Climbing Carabiner Uses 

The wide variety of carabiners on the market can be a little overwhelming. That is why, when you are shopping for climbing carabiners, it is a good idea to know what exactly you need them for. This can help narrow down the search and help you get ones with features suitable for your unique climbing goals. 

Belay Devices

Whether for belaying or rappelling, you will need to carry belay devices on your harness. To use these devices, you need a carabiner to attach them to your belay loop or an anchor system. 

Only a locking carabiner should be used for a belay device, so as to eliminate risk of the carabiner’s gate opening as a result of getting hit by an object (like your hand or other gear on your harness). This applies to all belay devices, from ATCs to Grigris. 

Features like a wide gate opening, smooth edges, and keylock nose are beneficial because they allow for easier loading of a belay device and rope – especially for devices like the GriGri, which have a rather small opening to load onto the carabiner with clunky external dimensions.

Although your run-of-the-mill locking carabiner works just fine with almost any belay device, carabiners (like the Black Diamond GridLock Screwgate) with “shields” and L-shaped bars resting underneath their gate also provide an added protection against cross-loading. 

Belay Devices

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These sorts of simple mechanisms block the rope-and-belay-device attachment from sliding down the carabiner, which can cause the carabiner to flip and thus load it from an undesirable point. 


If you are lead climbing outdoors, you will need quickdraws. Quickdraws are what you clip into the bolts as you make your way up a sport route. 

Quickdraws come with two carabiners, attached to each other with a piece of webbing  – also known as the “dogbone”. 

Carabiners for quickdraws should be non-locking, with either standard or wire gates.  This is because they need to be easily and speedily clipped. When on point, climbers don’t have the time to clip the rope in AND screw-lock a carabiner shut. 

 Although there are risks that come with non-locking carabiners on quickdraws, having healthy leading practices like not back-clipping and avoiding routes that are unsafely bolted can greatly mitigate them. 


Cleaning Gear 

On an outdoor rock climb, when a route is completed, it must be cleaned. 

No, this does not mean brushing off the rocks (although, it is  a common courtesy to do so in spots you’ve left a lot of chalk or tick marks). 

Cleaning refers to the act of retrieving all of one’s gear on the route. In the case of sport lead climbing, this means the quickdraws. 

There are multiple ways of cleaning a route at its anchors. The best way is via the method shown in this video by the American Alpine Club. But, not all anchors are the same. Some may not have big enough quicklinks to pull a bite through, and others may be set up for rappelling only. 

When learning how to clean – hopefully by a certified instructor – it is important to understand all the methods to be prepared for any anchor scenario. Outdoor climbing areas are the wild west compared to climbing gyms in terms of consistency in bolting ethics. Don’t go out until you know you are ready for any unexpected turn of events!

If you must go off belay in order to clean (i.e. if the quick-links are not big enough for a bite of rope to be pulled through), you must clip directly into the two anchor bolts at the top of the route. Make sure you communicate loud and clear with your belayer while doing this, and even notify them of how you plan to clean before leaving the ground. 

Ideally, the climber will use two slings running through both of their harness’s hard-points, with locking carabiners clipped through the slings, to clip directly into the anchor bolts. 

You should use locking carabiners while going “direct” (clipping yourself into the anchors in order to clean) so there is no risk of them opening.

If you are clipped directly into an anchor and taken off belay to clean, you only have two redundant points of safety -the carabiners (attached to you via slings) clipped into the anchor hardware. You no longer have your belayer and the rope to catch you, along with the many draws you clipped into on your way up to the anchor. 

Because of the reduced number of redundant points of security in this unique instance, it is important to maximize the effectiveness of the two that you do have.  

Anchors can sometimes have a lot of other moving parts that get in the way, such as quickdraws and carabiners. These things, combined with potential rock protrusions from the wall, could jam into your carabiners’ gates and cause them to open. 

With locking carabiners, you no longer have to worry about this happening. The gates will be secured shut. 

Building Anchors for Top-Roping and Multi-Pitching

Although a couple of sturdy quickdraws facing opposing directions will do, you can also build an anchor for top-roping to reduce wear on your sport gear. 

If you’re planning on going multi-pitching, make sure you 100% know what you are doing before starting up that route – because you will need some important knowledge on building anchors systems suitable for top-down belaying. 

Ideally, before starting on a multi-pitch, you will fully understand how to a) lead climb, b) go direct to a bolted anchor, c) build the appropriate anchor system to belay off of and, d) accomplish a “direct belay” using a Guide ATC/Reverso or GriGri. 

While climbing a multi-pitch route, you and your partner have to be able to ascend hundreds or even thousands of feet. To do so, the route is broken up into “pitches”, or sections of wall scalable using a single average-length rope and separated by anchor points. When the lead climber arrives at an anchor, they must then belay their partner up to them. Because they are belaying from above the climber (instead of from the ground), they must use a special method – informally referred to as “top-down belaying”. 

There are many different styles of anchor systems you can build that can adequately support a top-down belay. Remember, though – the more points of redundancy, the better. Having an anchor that can be equalized is also important. Equalization means that the anchor system weights the anchor points it’s attached to equally

One of the best and most convenient anchor systems for bolted multi-pitch routes is the “quad”. The quad can be made on the ground before climbing, carried on the gear loops of your harness, and quickly attached to anchor points. 

A lot of climbing destinations with multi-pitch routes are not bolted, and therefore require extensive skill in traditional gear. However, there are some bolt-clippers’ paradises, including the breathtaking El Potrero Chico in northern Mexico.

A great anchor that is self-equalizing and is popularly used in top-roping and trad multi-pitch is the sliding x

Before you go up a route, know what type of anchor system and top-down belay method you plan to use and how to build it. Also, know how many bolts (or the average number of traditional gear placements) there are for each pitch. The type of anchor you use and the amount of protection there is on the route will guide you in how many quickdraws and how many carabiners you should bring. 

You AND your partner should always bring two sets of enough carabiners to:

  1. Use your belay and rappelling devices both on the ground and on the wall
  2. Attach yourself to an anchor (at least two points, for redundancy)
  3. Attach your anchor system to the anchor points

Although you want to reduce the weight you have to carry up a big wall, it is a good idea to also have extra carabiners on your gear loops just in case you drop one or accidentally miscalculate how many you think you’ll need. 

Technical Specifications of Rock Climbing Carabiners

Types of gates and noses are important things to consider when looking at carabiners. However, there are some other features that you should also be aware of. (I know, who would’ve thought such a small and simple mechanical device would be so…complex. You’re in deep now, buddy!) 


There are several different carabiner shapes. Although they all can do the trick for just about anything, some are better than others. Ultimately, most quickdraws on the market have the same type of carabiner (Asymmetric D-Shape, purportedly the best shape). Shape matters most when considering carabiners for particular things, like for belay systems and aid climbing gear. 

Pear (a.k.a. HMS)

Pear (a.k.a. HMS)

Pear-shaped carabiners have a small runner’s end, a large gate-opening, and a very wide, gently rounded rope basket best suited for accommodating multiple items or bulkier gear. Some refer to it as the “HMS” carabiner as it is also ideal for use with a Munter hitch. 

Suggested HMS: PETZL – William, Locking Carabiner

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D Shape

D Shape

D Shape carabiners have an identical (symmetrical) runners end and rope basket – both with a slight peak towards the spine. This is the strongest shape, albeit one of the more expensive.

Suggested D Shape: DMM Phantom Screw Gate Carabiner

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Asymmetric D Shape

Asymmetric D Shape

The Asymmetric D carabiner is like the D shape carabiner – except the runners end has a smaller width than the rope basket. The minimized runners end reduces its weight without sacrificing its large gate opening, making it a more appealing option than the D shape. 

Suggested Asymmetric D Shape Carabiner: Black Diamond Litewire

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The oval shaped carabiner looks like a  symmetrical oval.The runners end and rope basket are equal in shape and size, slightly bowed in their center (versus arching closer to the spine like the D shape). Oval rock climbing carabiners are pretty old-school, and so are not seen very often anymore except for aid climbing. Their heavier weight, smaller gate opening, and lesser strength makes them a less appealing option in comparison to the other carabiner shapes. 

Suggested Oval Carabiner: Black Diamond Oval Keylock

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Strength Rating

If you look closely, you will see “kN”, followed by three sets of numbers on the spine of the carabiner. These numbers are accompanied by arrows and an image of an open, flat carabiner. All of this comprises the carabiner’s strength rating

There are three sets of numbers because there are three directions in which the carabiner is tested, or rated, for its ability to be loaded with force (measured in kilonewtons).

Ideally, the carabiner should be loaded along its major axis. This is when the carabiner is hanging in its proper up-right position. 

However, there is a possibility for the carabiner to be in one of a few different positions when impacted with the weight of a falling or a hanging climber. Here are those three positions, or axes: 

Strength Rating

As far as strength ratings go, the higher the numbers, the stronger the carabiner. You don’t need to worry about paying the numbers too much attention, though, as certified climbing carabiners should all have strength ratings adequate enough (at minimum) to withstand all of the sport’s potential forces. 

If you’re shopping for carabiners and are torn between a couple of choices, you could use strength rating as a deciding factor. That being said, with greater strength often comes greater weight! 


After the strength rating, the carabiner’s certifications should be listed on the spine. For a climbing carabiner, this means the acronyms “UIAA” (International Union of Alpine Clubs) and/or “CE” should be inscribed. 

The certifications ensure that the carabiner fulfills necessary safety standards for rock climbing equipment. 

According to the UIAA, these standards include the ability of the carabiner to have a “static strength of more than 20 kN” along the major axis, which is “more than the worst conceivable fall in a climbing accident”. To put it into perspective, a lead climbing fall has a “maximum force of 5 kN”.

The “CE”  is actually a marker of products disseminated via the European Union; it is the EU’s stamp for a product’s safety. However, the EU actually relies upon the UIAA’s recommendations for such standards in the realm of climbing equipment.

So, in a way, the UIAA stamp matters most. 

For a more extensive explanation of the relationship between the “UIAA” and “CE” markings, check out this article


According to some climbers, even the tiniest bit of extra weight can be the difference between a send or a bust. According to others, it’s merely “training weight” and will only help you climb stronger. 

Regardless of these varying opinions weight plays a factor in climbing, but, with strings attached (pun intended). 

Ultralight rock climbing carabiners sound great, but they come at a cost. They can be less durable: as the size of the gate’s rod stock is reduced, so is its strength. They can also be worn more quickly by rope running through them, due to their narrower rope baskets and runners ends. Their reduced size and weight can also make clipping more annoying as a result of being more difficult to manipulate. 

For these reasons, ultralight carabiners are better for occasional use on project burns. Consider purchasing heavier (aka. standard) rock climbing carabiners for all your other less-than-high-stakes climbing needs. 

Gate Clearance 

The gate clearance, or gate “open” clearance, refers to how wide the carabiner’s gate opens. This can also include the depth of the runner’s end underneath the gate, which your finger inevitably slips down into while clipping the rope. 

So, if the gate clearance is small, you will have less space to maneuver the rope in with. In the worst case scenario, your finger could even get caught between the gate and the spine for a small instant. Too large of a gate clearance could also make clipping awkward. 

When shopping for carabiners/quickdraws, it is a good idea to check them out by mock-clipping rope into them. Pay attention to how your fingers feel as they slide into the gate and down, and consider that there will be even less space with the actual rope in there. 

Gate Lash 

Gates are meant to open and close. However, it’s not so great when gates open in the instances they’re not supposed to. And there are a couple ways in which this can happen:

  • When the vibrational force of the rope pulling quickly through the carabiner (caused by a lead fall) is too great for the tensioned spring holding the gate in place, it can make the gate “flutter” open and closed
  • When a rock protrusion or object wedges into the gate
  • When the carabiner’s spine hits hard enough against the rock or other objects

You can reduce your risk of experiencing gate lash by selecting climbing carabiners that have wire gates or even tighter spring tensions. Wire-gates are less prone to gate lash than standard gates. Obviously, locking gates – when fully locked – do not face this issue, but are not useful on quickdraws. 


There is a LOT of science that has gone into making sure rock climbing carabiners are strong enough to hold mondo-whippers, withstand all sorts of weather and years of use, and make the process of getting off the ground and back down again ever more seamless. 

It is no wonder the carabiner is one of the most popular icons associated with rock climbing. 

As with all climbing gear, there is an overwhelming amount of technical information available to help inform your purchase decisions. It is a great idea to do your research, but don’t spend too many hours nerding out over the stuff (unless you’re finding enjoyment in it, of course!).

Be certain you are getting what is appropriate for your needs, at minimum. Then, you can discover what rock climbing carabiners you prefer most through use at the crag. 

For example, certain carabiners, like the L-shaped bar ones, can be annoying to load your belay device onto.

You may or may not find it worth the added protection against cross-loading – which is not that big of a deal, and especially not if you are super attentive to your devices.

Or, you may really appreciate the way it keeps your belay device from sliding around inside the carabiner. But you won’t know for sure until you try it out!

Happy carabiner hunting!

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Published by Melissa Kochanowsky

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