Climbing Carabiners: How Do You Pick the Right One?

Climbing carabiners come in all shapes and sizes. Some are big, some are small, some are ovular, while others have a narrow end and a wide end. You might be able to lock the gate, while others don’t have this feature at all. There’s a lot to think about, and these few differences are only scratching the surface!

Various aspects of climbing require carabiners that have different functions and designs. If you’re belaying, you need a pear shaped, locking carabiner, but if you’re making your own quickdraws, “locking” is the last word you want to hear. So how do you know what to use and when? We’ll walk you through the different styles of climbing carabiners and how to pick the right one.

Key Takeaways:

  • Asymmetrical “D” Shape: Ideal for quickdraws, featuring a larger gate opening and reduced weight.
  • Pear Shape: Excellent for belaying and rappelling, with a wide/narrow design for optimal usage.
  • “D” Shape: Known for strength, suitable for utility purposes like gear attachment.
  • Oval Shape: Versatile and cost-effective, great for utility purposes, especially in aid climbing.
  • Check the kN rating on the carabiner for weight capacity, ensuring it meets safety standards.
  • Consider whether you’ll need a locking or non-locking carabiner.

Carabiner Shape

carabiners with a belay device rope and zippo lighter and knife

Asymmetrical “D” Shape

By far the most popular climbing carabiner out there, almost every climber probably has at least one of these in their arsenal. They are what you’ll typically find on each end of a quickdraw, because they have a larger gate opening than most of the other styles of carabiners. This makes clipping a lot easier, which is precisely what you want in a quickdraw. And because of their asymmetry, these carabiners are narrower at one end, which is helpful for reducing weight.

Pear Shape

Similar to the asymmetrical “D” carabiner, the pear shape has a large gate opening that makes it a great option when you’re looking to clip it to something fast and easily. The shape makes it wide at one end and narrow at the other, which is precisely what you want when you’re belaying or rappelling. The narrow end should rest on your belay loop so that you can have a smaller pivot point for your belay setup. That also lets your belay device stay on the wider end, where it will have more room to rest comfortably. 

“D” Shape

These carabiners are designed for strength. By nature, they bear loads off-center, directing all of the force away from the gate (which is the weakest part of the carabiner). Because of their exceptional strength, you can get away with using a smaller “D” shape than you might otherwise need with a different shape of carabiner. The downside is that they do tend to be heavier than their asymmetrical counterparts, and their gate openings aren’t as large either. Because of this, they aren’t as suitable for jobs where clipping is necessary. Instead, they make great options for utility purposes, like attaching gear to your harness.

Oval Shape

Finally we have oval shaped carabiners, which were the original style back in the day. These are a really versatile option and tend to be cheaper than the other shapes listed above. Like “D” shaped carabiners, these are really popular for utility purposes because their rounded sides are able to hold more gear. Unfortunately, they are a weaker style, and not ideal for extreme load bearing jobs. But if you enjoy aid climbing, you won’t find anything better to use. Because of the symmetry and rounded bottom, runners will rest nicely in the center without shifting from side to side while weighted. 

Strength and Kilonewtons

That should give you a better idea of what carabiner you should buy for your personal needs. However, there’s much more that you’ll need to know before you go ahead and pull out your credit card. Perhaps more importantly than anything else, check to see how much weight your climbing carabiner can comfortably hold. 

Carabiners measure weight in terms of kilonewtons. If you look on the spine of the carabiner, you may notice a marking that looks something like this: 

carabiner strength rating

The kN is an abbreviation for “kilonewton,” and one kN is equal to about 225 pounds of force. Remember that force is not the same as mass or weight – instead, it’s equivalent to mass times acceleration. Every carabiner has a kN rating for its length (major axis), its width (minor axis), and while the gate is open. In the picture above, the rating for the length is 25 kilonewtons, the rating for the width is 7 kilonewtons, and the rating for when the gate is open is also 7 kilonewtons.

If you’re buying a climbing carabiner from an outfitter like REI, all of their gear has already passed UIAA standards of safety, so feel free to grab whatever one you’d like. Generally speaking, I like to use carabiners that have a kN rating of 20+ on its major axis, just to be safe. Even if you go with a rating of 8 kN, it will still withstand almost 2,000 pounds of force, which is probably more than you would ever get close to hitting. However, wouldn’t you feel better knowing that your carabiner could take two to three times that much force without breaking? I know I would.

Never EVER use a carabiner that doesn’t have a kN rating on it. These are not designed for climbing, and are totally incapable of taking the amount of force that you’ll be putting on them. 

Carabiner Weight

two black diamond carabiners laying next to each other on a sidewalk

All right, let’s talk about weight now. While not a safety concern, we all know that it can be difficult enough just to pull our own body weight up the wall. Why make things harder for ourselves by getting heavy gear to carry with us? By nature, some climbing carabiners tend to be heavier than others, such as the “D” shape options. However, lighter usually means smaller, and that isn’t always a trade off that’s worth making.

One easy way to reduce weight without cutting back on size is by getting wire gate carabiners. Instead of having a solid gate that you most commonly find, wire gates only have a loop of stainless steel. The reduction in material means there will be less for you to carry up. While it might seem like an insignificant amount, trust me when I say that every ounce counts!

While wire gate carabiners definitely have their pros, they aren’t my personal favorite. Wire gates usually sport a non-keylock style, meaning the carabiner hooks into itself where the gate connects to it. This leaves a lot of room for snagging, and while it’s not dangerous, it can create more hassle than I like to deal with. But the fact that they are lighter and cheaper than other climbing carabiners make them an attractive choice for people shopping on a budget, or for those who like the style.

Locking vs. Non-Locking

a locking and non locking carabiner next to each other on the sidewalk

Now we’ll talk about locking vs. non-locking carabiners. One isn’t better than the other, but they are each essential for their individual tasks. Locking carabiners should always be used for belaying, as an extra level of security to make sure the belay doesn’t come undone. The same can be said for rappelling, the carabiners you keep on your PAS, and a few other situations.

Non-locking carabiners are vital for moments when you can’t afford to take the time and effort to unlock them before use, or there’s just no need for them to be locked. Examples of this would be their function in quickdraws, some anchor building, and utility purposes.

There are a number of ways that a climbing carabiner can lock, but the most common is arguably the screwgate. Found in the picture above (the silver carabiner), you might notice the blue cylinder located on the gate. When twisted, this can move either up or down depending on which way it’s being rotated, locking or unlocking it respectively.

Some gates have magnets on them as a locking mechanism, though it’s a less popular style because it isn’t as secure as a screwgate. A few of my friends have used this type of carabiner while belaying, and I’ve never had an issue with it; however, if you like having that extra peace of mind, I’d go with a different carabiner.

Finally, there are some carabiners that you can only unlock by twisting the gate and pulling back. These aren’t as common, though they work well for most circumstances. Just make sure the gate closes all the way when you release it, as this style can get get stuck in a “partially open” position.

Gate Shape

When picking the right carabiner, the shape of the gate is really the final thing that you need to consider. Since we’ve already talked about wire gates, I won’t mention them again in this section, focusing instead on the remaining two: straight gates and bent gates.

Straight Gate

Carabiners with a straight gate tend to be more common, and are often used in quickdraws, when racking gear, and for other utility purposes. There’s nothing inherently bad about this gate style, aside from the fact that it’s heavier than a wire gate, so they’re favorites among many climbers. As it is with nearly all carabiners nowadays, the gate is spring loaded so that it closes on its own once you take pressure off it.

Bent Gate

As the name suggests, this carabiner has a gate that bows inward. Like the straight gates we just talked about, bent gate carabiners are quite versatile and can be used for almost any task. However, because the bend in the gate takes up some room on the inside of the carabiner, they aren’t widely used for holding bulky gear. Instead, this design was created for one main purpose: rope clipping.

When trad of sport climbing, you’ll need to clip your rope to a quickdraw for protection along the way. The bent gate makes it easier for the rope to fall into place, instead of sliding right off the carabiner while you’re fumbling around.

The Final Breakdown

woman rock climbing big wall crimp carabiner

Carabiners are a climber’s best friend. If you get even remotely serious about the sport, it’s likely that you’ll have a few dozen of them at any given point in time. They’re a necessary connection point for many climbing procedures, such as belaying, rappelling, and anchor building, but they’re also incredibly convenient for utility purposes as well. Climbing gear adds up quickly, and you’ll need to keep most of it on your harness (I’m looking at you, trad climbers!), so carabiners are handy tools to keep everything organized and secured.

So how do you know what to use and when? Here’s a nifty chart that may help you answer these questions:

Type of CarabinerUse
Pear ShapeGreat for belaying and rappelling
Oval ShapeGood for utility purposes, like racking trad gear
D ShapeUsed for load bearing purposes because of their strength
Asymmetrical D ShapeSame as D shape, but lighter weight because one end is narrower
Type of GateUse
Straight GateStrong and easy to use, it’s a good “jack of all trades”
Bent GateGreat for rope clipping because of the bend – used in quickdraws
Wire GateIdeal for cutting back weight, though less durable than other gate types

It’s hard to go wrong when picking carabiners. As long as you know when they should lock, how many kilonewtons they can withstand, and the size of the gate opening, there isn’t too much to be concerned about. Once these essentials are taken care of, test the gate to make sure it operates smoothly, and make sure it’s something that feels and looks good. Chances are you’ll be using it for a long time.

Meet the Author!

By the age of 20, Spencer had already tackled some of the most famed mountain ranges in Europe, Asia, and North America. His mission is to help others accomplish their own outdoor-related goals, even within the time constraints of a 9-5 job and a busy life schedule.

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