Carabiners

for

climbing:

Everything

you

need

to

know

Carabiners  go a long way in helping you get to the top. As they have to fulfill strict production requirements and safety standards, you can rest comfortably knowing that they will keep you firmly tethered to rock and climbing rope. Always check for European CE or global UIAA safety certification when choosing your equipment, which indicates the maximum breaking load for axial, transverse and open gate loads. Or, in other words, how much strain a carabiner can safely sustain lengthwise, sideways and while open. These ratings can be found etched into the spine of your carabiner. 

At a glance: Types of carabiners

Structure

1. Nose

2. Bend

3. Spine

4. Gate

So what is a carabiner actually made of? And what are the nose and spine? Here’s a quick glossary on some key terminology: A carabiner is made up of the frame, spine, nose, and gate. The gate is the moving component that connects to the nose and snaps into place. The nose transitions into the frame (sometimes called basket). The spine is directly opposite the gate. Depending on the type of carabiner you’re using, all these components can be very different in shape. Here’s an overview of the various types available: 

Shapes of carabiners

• Oval or Type X: These classic carabiners are only rarely used in climbing these days because their load bearing capacity is a lot lower compared to modern types, and they are a whole lot heavier. They are mostly used by rope access climbers or arborists, as well as in outdoor education. However, oval carabiners also work in combination with a GriGri or other types of semi-automatic belay devices, as well as with nuts and more.

• D-shape or Type B (basic): D-shaped carabiners soon replaced their oval counterparts, offering a higher load bearing capacity and simplified handling. Their asymmetric shape means reduced weight while increasing the size of the opening. These types of carabiners are particularly suitable for anchor building and connecting different anchor points with one another, where no heavy load is involved.

• HMS carabiner (connector for belaying), Pear shape or Type H: The generously curved, large loop provides plenty of space for HMS knots, which is also where the name comes from. This type of carabiner is the one that’s used most frequently, especially for belaying and abseiling. 

• Klettersteigkarabiner or Type K: “Klettersteig” or “via ferrata” carabiners come with special closing mechanisms to make clipping them quick and easy. There are two types of closures: (palm) grip safety and thumb safety.

• Maillon Rapide or Type Q: This type of carabiner is a locking carabiner made of steel, intended for use in intermediate belay points. When wall climbing, they are often used for creating leave-in-place abseil anchors and in top-roping.

• Extra large opening gate: These carabiners are particularly great for via ferratas, ice climbing with gloves, and perfect for climbers with large hands. The size of the opening also indicates how much you can attach in the way of ropes, slings, etc.

How much weight can my carabiner hold?

Axial load

First and foremost, carabiners are designed for sustaining axial loads with the gate closed – perfect for the vertical forces you are exposed to while climbing. Strength ratings vary depending on the type of carabiner, typically ranging from 18 to 25 kN. If the weight load shifts to the wrong spot or the carabiner is wrongly positioned, this can significantly reduce its overall load bearing capacity. So make sure your carabiner is properly closed, without any rope or other fabric stuck between the nose and gate. Don’t let your carabiner lie flat against ledges, and avoid loading it in more than one direction at the same time.

Transverse load

Transverse load refers to the load placed on the spine and closure system of the carabiner, i.e. along the minor axis (sideways). The maximum breaking load ranges from 7 to 10 kN, which is only 35 % of the axial breaking load. So be careful when loading your carabiner, as there’s a chance it could break if you put too much weight on it.

Open gate load

Naturally the gate should always be properly closed – and stay that way, even when loaded to the max. That being said, it’s still possible that the gate accidentally opens. This can be as a result of gate lash caused by a fall, ice build-up on the biner, a dirty gate or objects being caught in the nose. This is often highly problematic, because the maximum breaking load will be drastically reduced – down to only 30 % of the axial breaking load. The maximum open gate load needs to be between 5 and 7 kN. So make sure to keep an eye on strength ratings when buying a carabiner!

Carabiner locking mechanisms: A guide

Carabiners can be divided into two types of gate closure systems. The basic variant, often referred to as normal carabiner or non-locking carabiner, and the much more secure locking carabiner, where the gate can be locked either manually or automatically.

Normal Carabiners

Non-locking carabiners, also referred to as snap-gates, are super easy to use and can be opened quickly, which makes them perfect for transporting equipment and quickdraws. The gate can be either curved or straight. Typically, the gate itself is spring-loaded, or the nose is fitted with a small hook into which the gate nestles. The latter can be problematic as there is always the risk of the hook catching in the gear or bolt loop. To prevent this, a number of cleverly devised alternative options are readily available, like keylock and wiregate carabiners.

Keylock

Keylock carabiners have a smooth notch where the nose of the carabiner and the gate interact, making both components fit together just like two puzzle pieces. This prevents the carabiner from hooking on anything from slings to gear loops, while also eliminating sharp points like the nose hook, which can damage the rope.

Wiregate

Wiregate carabiners are fitted with a looped stainless steel wire which connects to the nose. Because of the nose hook, there’s still the risk of the carabiner catching on something. So always make sure to check that the carabiner gate is properly closed. Both wiregate  and keylock  biners are very lightweight, meaning less mass overall. They also have a better breaking force when open, which is why they are widely used for quickdraws to reduce gate lash. The gate is the only movable component of a carabiner: The higher its mass, the higher the chance that the gate will accidentally open or break during a fall. Because of their reduced overall mass and the additional integrated wire tension, wiregate carabiners can help in reducing the risk of gate lash. They are also a great choice for ice climbing, as the gate is much less likely to freeze in subzero temperatures.

Locking carabiners

If you’re looking for maximum safety, look no further! Locking carabiners are the ideal choice for belaying and self-tethering, and connecting your belay device  to the climbing harness . They are particularly useful for belay stations or protection placement when multi-pitch climbing. You can also use them for building belays in top-roping – this not only reduces the stress on the material, but also helps extend the carabiner’s durability. 

Manual locking or screwgate carabiners

Screwgate carabiners are the most classic type of locking carabiners. You can simply lock them manually by closing the snap-gate and screwing on the threaded sleeve. Make sure everything is screwed on tight and in the right position, and that your brake line is on the same side as the carabiner’s spine. The great thing about screwgate carabiners: You can always use them like a regular carabiner, which comes in very handy when clipping into an anchor. If you were to use an auto-locking carabiner, you’d constantly have to hold the gate open or fully unlock it every single time. The downside of screwgate carabiners: The gate can sometimes accidentally open when rubbing against a rope or rock. If you want to use a locking carabiner with an HMS-knot, it’s best to use auto-locking carabiners – otherwise, the knot may unscrew the sleeve of the screwgate. When roping in, the vibrations caused by the running rope can also slowly unscrew the lock. A specific type of screwgate carabiner has been developed to prevent exactly that: the Screwgate or Smart 2.0. HMS. On top of the manual screw-on sleeve there’s a plastic flap for added safety to prevent the lock from accidentally unscrewing.

Auto-locking carabiner

Unlike screwgate carabiners, they automatically lock as soon as you close the snap-gate – enabling quick handling and providing a highly secure locking mechanism, which is vital for belaying, abseiling, anchor building or roping up. Especially when alpine and ice climbing, you not only need a sturdy climbing helmet  and climbing ropes  you can rely on in the most challenging conditions, but also high-quality carabiners to keep you safe. There are a number of auto-locking mechanisms available: slider gate, twist lock and tri-lock: The twist lock is a double-action auto-locking system where the snap-gate is fitted with an additional twisting sleeve which can also be opened fairly quickly by hand – provided you’ve had a bit of practice first. Tri-lock carabiners, also referred to as triple or safelock carabiners, can be opened in three simple moves, either via push-and-twist or pull-and-twist. Ball-lock and perma-lock carabiners are special variants of the trilock mechanism, where the twist sleeve is unlocked by pushing a button.

Especially if you’re sport climbing or just learning the ropes, auto-locking carabiners are the way to go.

What are HMS carabiners?

HMS is the abbreviation of the German term “Halbmastwurfsicherung”, better known as half clove hitch belay or Munter hitch. HMS carabiners are pear-shaped and have been specifically developed for a belaying technique using no additional devices, which is frequently found in alpine climbing. All you need is an HMS-carabiner and a rope. The large opening perfectly accommodates the HMS knot, and is fitted with a screwgate or twist-lock locking mechanism. Naturally you can also use HMS carabiners in combination with various belay devices  (e.g. GriGri). Information on which devices are compatible with your carabiner can usually be found in the instruction manual. 

Material carabiner

Careful: Material carabiners do not conform to any norms, and should not be used for climbing as they have neither the required stability nor fulfill the necessary safety requirements. Like the name suggests, you can use these types of carabiners to attach equipment like your chalk bag or water bottle to your backpack. These carabiners are available in many shapes and sizes, and are quite often used as key chain.

What materials are carabiners made of?

Steel vs. aluminum

Most carabiners are made of aluminum, which makes them very lightweight and durable. Compared to steel carabiners they show signs of wear and tear much more quickly. But while the steel variety is extremely durable, it’s also very heavy. That’s why it’s best to use them for heavy loading, for example in fixed quickdraws  when indoor climbing or for abseiling on a via ferrata. Aluminum carabiners should never be used on anchor points.

How to use carabiners

Carabiners for top-rope climbing

For top-rope climbing you’ll need a carabiner and belay device. You should choose a carabiner with locking mechanism, for example an HMS, safe-lock, tri-lock or ball-lock carabiner. 

Quickdraws for lead climbing

In lead climbing, the rope is attached to intermediate belay points. In the gym, these are usually already in place. When climbing outdoors, you’ll need at least 10 quickdraws and an HMS carabiner and a sling, as there are usually no pre-fixed belay points on the wall.

Carabiners for ice climbing

When ice climbing, you should always use a wiregate carabiner, which is a lot less likely to freeze shut.

What carabiner to use for daisy chains?

On challenging routes, daisy chains are useful if you need to rest in between stretches. It's best to use a long sling/runner and an HMS carabiner.

Checklist for buying carabiners

• What shape do you need?

• Is the load bearing capacity high enough?

• Closing mechanism: Do you need a locking carabiner, or is a spring-loaded gate enough?

• Nose: Compact or wiregate? 

• Single vs. two-handed: Do you need one or both hands to operate the carabiner?

• Type of use: Do you need a carabiner for belaying, a material carabiner, or do you want to attach a quickdraw?

• Color: When using the same type of carabiner for your quickdraw, think about color. This will help you know at a glance which one is meant for the rope, and which one is meant for the wall.

Get inspired

So what do the pros actually use? Our Mammut athletes  show you which carabiners they are happy to entrust their lives to. Whether you opt for a keylock quickdraw like Jakob Schubert , a belay like Lucia Capovilla  or a classic screwgate carabiner like Alberto Ginés López  – at Mammut, you’ll find the perfect accessory for any climbing activity!