All about carabiners

All about climbing carabiners

In this review we will talk about the different types of carabiners, their features and applications. Let's touch on such important aspects as:

Carabiner design
Gate and lock
Common forms and uses
Types of nose
Size and weight
Durability and certification
Maintenance: preventing jamming



Parts of the carabiner

There are more than a thousand variations of carbiner designs in the world, but in general, any of them can be considered according to five main components:

Spine of frame — the strongest part of the carabiner, which bears most of the load and weight

Spring-loaded latch - opens inward for attaching ropes, devices or other elements 

Locking sleeve - serves to lock the latch

Nose - part of the carabiner that responds to the latch 

Gate - gap between open latch and nose




Carbiners are divided into two main types:

- carabiners with a locking latch (with a sleeve)

- carabiners with a latch without a lock (without a sleeve). This type of carabiner is used where the likelihood of accidentally opening of the latch is very low. For example, on quickdraws or when lifting loads

Types of latches without sleeve:


carabiners without sleeve carabiners without sleeve carabiners without sleeve

Latches are either solid or wire.
Wire snap carabiners are lighter, but most designs have a hook-shaped nose that sometimes snags on clothing or other equipment.
Both solid and wire latches can be straight and/or curved. A straight snap carabiner is typically used at the end of a quickdraw to attach to an anchor. The carabiner with a curved latch is oriented towards the rope, making it much easier to attach the rope to the quickdraw.

Carabiners with sleeve

The sleeve - or lock - serves to lock and prevent accidental opening of the latch.

carabiners with sleeve carabiners with sleeve

- Screw-on coupling - lock

Convenient and reliable, carabiners with such a sleeve are cheaper than similar ones with an automatic lock. Due to its simplicity, reliability and resistance to external influences, it is recommended for use in sports mountaineering. In some situations, the clutch may still come loose; you need to remember this and periodically check its condition on the carbines that are currently in use. Some manufacturers put bright markings on the end of the latch to help determine how tight the coupling is.

carabiners with automatic lock carabiners with automatic lock carabiners with automatic lock

- Automatic clutch – lock

The latch with such a clutch is always in locked mode. This is a more complex design and, as a result, its reliability is inferior to screw locks. It is often difficult to open a carabiner in bad weather, when moisture trapped in the lock freezes and prevents opening. Carabiners with automatic locking are considered standard for industrial mountaineering and high-altitude work. Here their advantages are obvious: the time for fastening is reduced and the carabiner does not require further control. They are also widely used in transporting, in rescue operations, etc.
Structurally, such coupling locks are divided into two-position and three-position, depending on the number of positions for unlocking.

- Special locks: magnetic, ball and double latches

Some carabiners come with special locks that provide an automatic locking feature due to a unique lock design.
Magnetic carabiners are popular for their speed and ease of opening and closing. As the name suggests, the latch has magnets that keep it closed.
Ball lock carabiners are similar in operation - they require a small ball to be pressed inward to release the latch.
Double-latch carabiners have two latches that are positioned opposite each other: one opens inward and the other opens outward. They may be a little uncomfortable at first, but they are a great option if you are looking for a passive locking mechanism. Despite the fact that special locks are technologically advanced, they have their limitations. Magnetic and ball lock carabiners are not intended for use in harsh weather conditions - the mechanisms may freeze. Double-latch carabiners are almost impossible to use in the cold with thick mittens.



The next thing you need to pay attention to when choosing a carabiner is its shape. It should be suitable for the intended use. Carabiners come in four basic shapes, each suitable for specific tasks

D-shape carabiner

Standard D-shaped carabiner

D-shaped carabiners are strong and durable. This carabiner is an excellent choice for a wide range of mountaineering tasks. The asymmetrical shape allows the load to be distributed closer to the spine frame, where the main axis is strongest


Asymmetric D-shaped carabiner


Asymmetrical D-shaped carabiner

Improved D-shape design with larger rope basket. This makes the structure lighter and stronger. The offset also allows the latch to open wider - this is especially useful in smaller carabiners, and is a good option for quickdraws.

  Wider gate opening

HMS carabiner

HMS carabiner

This pear-shaped carabiner, sometimes referred to as an "HMS" ("Halbmastwurf sicherung" or Munter Hitch Belay), is designed for rappelling and belaying with a device or using a UIAA knot. The increased gate opening makes it easier to attach belay devices. The round rope basket helps reduce wear and tear on the rope and carabiner. They are slightly heavier than usual, but the increased internal volume allows them to be used at stations as a central master carbine.

  The round rope basket reduces rope wear and increases the life of the carabiner

        Oval carabiner

Oval carabiner

Oval carabiners are geometrically the weakest, but they have many useful uses. The symmetrical shape helps center the load when attaching loops or pulleys to the carabiner. Sometimes you'll see people using ovals to set up a carabiner-brake rappel for a double rope rappel.

  Symmetrical shape
  Use in some technical techniques (guard knot, carbine brake)
  Fastening block rollers

Special carabiners

special carabiners special carabiners special carabiners special carabiners special carabiners

There are other types of carabiners that are used for specific purposes and tasks: for via ferrata, for industrial mountaineering, for belaying on metal structures, connecting elements, etc.
We will consider their varieties and purposes in a separate article.


nose of carabiner nose of carabiner
You may not notice it until you start using the carabiner, but the nose is actually very important. Not only from a safety point of view, but also from the point of view of ease of use while climbing.

The nose is where the latch meets the carabiner in the closed position. This connection is very important for the overall strength of the carabiner. The notch in the nose engages the slot in the latch and holds it in the closed position when the carabiner is applied. The classic hook-shaped notch often snags on equipment and makes the carabiner difficult to operate. Therefore, modern types of carabiners, especially those with a solid latch, are produced with a more convenient, smoothed nose shape without a hook. However, this problem is not solved on all models on wire latch carabiners.


Once you have decided on the latch type and shape, size and weight are the next important criteria to consider when choosing the right carabiner for your needs.
Although carabiners are generally quite lightweight, it is important to consider the total weight of multiple quickdraw carabiners or the weight of a standard set. Size also matters. In addition to size affecting weight, a smaller carabiner also has a smaller latch, which may be more difficult to thread the rope and belay device into (compared to a larger carabiner). So how do you balance size and weight? 

full-sized carabiner

Full size

Most people prefer to use full-size carabiners. Especially when they are supposed to be used in harsh conditions, wearing thick gloves

small carabiners

Small and mini sizes

Sometimes you can save on weight, for example, when picking quickdraws or friends/camalots. You can use mini carabiners, which are as strong as full-size ones and weigh only 22 grams. In these cases, saving a few grams can make a big difference


How do manufacturers reduce weight without sacrificing strength? This is an interesting question.
Today, almost all mountaineering and rock climbing carabiners are made from hardened aluminum alloy. This is a high-strength material that provides the necessary lightness, ductility and strength at a reasonable price. While the material of carabiners usually doesn't vary much from brand to brand, the difference in strength to weight ratio comes from the design of the product.
The rope basket and carabiner shaft are places where weight can be manipulated without sacrificing strength.
Manufacturers are also experimenting with the cross-section of the rod - due to it, they can reduce weight, but meet the strength requirements. The cross-section of the rod can be round, H-shaped or other shape. When choosing a carabiner, pay attention to the area of the rod near the rope basket: the thinner the rod in this part, the faster the carabiner will wear out and the rope will wear out.
Carabiners with a round bar are considered more wear-resistant, so they are preferred to be used in conjunction with descenders and belay devices.

Carbines are also made of steel. Even though steel carabiners seem to be the best option in terms of strength and price, climbers still prefer aluminum/duralumin options because they are lighter. With the same shape, an aluminum carabiner will weigh from 22 to 60g, and a steel carbine 200-300g.
Designed for industrial use, steel carabiners tend to be more durable and strong. You can find them with forces up to 60kN, making them almost 3 times stronger than any aluminum equivalent. However, this amount of force is rarely required for traditional climbing. Nevertheless, in sports it is common to see steel carabiners used as fixed gear - simply because they are more resistant to rope wear and tear.
In general, it is still recommended to have a pair of steel carabiners to use in high friction areas when training. 


certification of carabiners

The carabiners that you use for belaying in mountaineering or rock climbing must be certified - only then can you be sure of their strength. Do not use carabiners that are damaged or frayed, even for secondary purposes (eg, for hanging equipment), because they may be needed for belaying and you will use them in a hurry without noticing the damage.
When purchasing carabiners, be sure to check that they have the "CE" and/or "UIAA" marking, and the name of the manufacturer (preferably a well-known/reputable one)
What do these letters mean? The fact that the carabiner meets the minimum strength requirements specified in the certificate.

Strength is assessed in three areas:
- along the longitudinal axis - in this orientation the carbiner is designed for maximum loads
- along the transverse axis. In diameter the carabiner can withstand almost three times less. Strength is further reduced if the carabiner is rotated (avoid this position)
- along the longitudinal axis with an open latch

For reference: 1kN corresponds to a force of 101 kg. That is, 23 kN corresponds to a maximum load of 2300 kg.

8. MAINTENANCE: preventing the carabiner from jamming

Cleaning your carabiners isn't usually done, but doing so a couple of times a year might just make your gear more enjoyable to use.

- The carabiner latch is stuck or is slow to close/open
- Grinding sound caused by sand, dirt or salt in the latch shaft.
- The clutch is jammed or it doesn’t open well

To clean, simply soak the carabiner in warm soapy water for 5 minutes, and then brush all parts with a soft brush, especially paying attention to the hinges and joints. Afterwards, rinse, dry well and lightly lubricate the latch axis.


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