Carabiner Information

Picking the right carabiner is extremely important, because the product you choose will be holding your life! The main function of a carabiner is to connect things together: a climber to the wall, a window washer to the scaffolding, a stretcher to a helicopter for evacuation and sometimes your keys to your belt loop. Given all the different uses, there are literally hundreds of different carabiners to choose from, making it all the more important to know how to choose the right one. Looking at the type of use, combined with your personal preference, will help to narrow it down.

The two primary materials used are Aluminum and Steel. Both are very strong but have very different uses primarily due to weight.

Aluminum is significantly lighter than steel and is therefore far more popular in the outdoor and climbing industries where weight is a major factor.

Steel is used more commonly in the industrial industries due to its extreme strength and durability.

There are two types of “noses” commonly used in carabiners.

The first and older type is a “Pin Nose.” The pin nose uses a pin in the gate and a notch in the nose of the carabiner to maintain structure and strength. This type is typically easier to manufacture (so more affordable) and typically stronger.

The second type is referred to as a “Key Nose” and does not have a pin and notch. The advantage to the key nose is that there is no notch to snag on anything while clipping or unclipping. Products featuring a Key Nose carabiner are marked with “K” insignia above.

The modified “D” and HMS have one side biger than the other to allow for more gate opening. The HMS, or pear, shaped carabiner was originally invented for use with th Halbmastwurf Sicherung knot that was used for belaying. These shapes are perhaps the most popular for all industries and are the preferred choice for use with a belay device.

This shape pushes the load to the back “spine” of the carabiner allowing the weight to be carried primarily by the spine and less by the gate, making the carabiner stronger and lighter.

The original shape of carabiner is the “Oval”, the symmetrical shape keeps the load from shifting creating more stability, but is typically not as strong as other shapes.

A captive eye carabiner has two separate points to tie in to prevent any cross loading of the gate. Some carabiners have the option of adding a captive eye pin to turn a modified “D” into a captive eye, while others are “true” captive eye.

Due to the variety of industries and uses for carabiners, there is an endless variety of new carabiners constantly coming onto the market. Some are a certain size or shape that works very well for one specific use like the Ladder Hook and Rebar Hook that is large enough for a fire fighter to clip onto a sprinkler pipe in an emergency, and the Contigua mini carabiner that is keychain size but strength rated to 5,000lbs.

The type of gate on the carabiner makes a big difference in what the carabiner is used for. The two main types are locking and non-locking.

Non-locking carabiners are for general use and when clipping quickly is important. The 3 types of non-locking gate are straight, bent and wire. ALL carabiner gates are spring loaded to ensure gate closure upon release. If a gate does not close automatically it is time for a new one!

The straight gate is the most common. The straight line across the opening tends to be a little stronger than a bent gate carabiner.

A bent gate allows a quicker and more ergonomic clip in, especially when you only have one hand available to clip a rope into the carabiner, such as when sport climbing.

A wire gate carabiner uses a loop of stainless steel wire as the gate. Even though it looks weaker, the wire gate is just as strong as a straight gate. The wire itself creates the “spring” to close the gate so there is no need for an extra mechanism, cutting down on weight. The other main advantage to the wire gate is since there is no spring mechanism, the gate will never freeze shut.

Locking gates come with a separate mechanism or sleeve to ensure that the carabiner does not open on accident. There are two basic types and once again, several variations of these types.

The screw gate is the most common and oldest style of locking carabiner. A sleeve must be manually loosened to unlock the carabiner then, tightened to lock the carabiner.

An auto locking carabiner uses a spring mechanism to not only close the carabiner but also to lock the carabiner as soon as the gate is released. The user then twists the sleeve to unlock and open the carabiner.

Another feature some carabiners offer is a “triple” locking carabiner which the user must push the sleeve up or down before twisting in order to unlock the carabiner, hence adding another level of safety. All triple-locking carabiners meet ANSI Z133.1-2000.

Strength is measured in kiloNewtons (kN) which is mass X acceleration. 1 kN is equivalent to 225 pounds. The minumum strength for most uses including rock climbng is 5,000 lbs or 22.2 kN. Other industries require higher minimum loads up to 60 kN. The overall strength rating of a carabiner refers to the carabiner being loaded along the “major” axis, which is along the main spine of the carabiner. The “minor” axis refers to the load pulling across the gate. The strength of the minor axis and the strength of the carabiner with the gate open are usually less than half the general strength of the carabiner. Some jobs have a minimum strength for the gate or minor axis.

Steel is most often the choice for industrial and high strength requirements. Steel can be tempered to be stronger without increasing the overall size of the carabiner too much, and can withstand much more abuse before breaking down. Anytime you are clipping a metal carabiner onto metal anchor or object it is important to use steel. Aluminum is a much softer material and will not hold up against steel, especially if a constant level of tension or movement is required. Dragging an aluminum carabiner across a steel cable will destroy the carabiner very quickly: however a steel carabiner will last for a long time, even under high use situations but definitely will weigh a bit more.

Plated finishes are now commonly used on carbon and alloy steel carabiners to protect them from surface oxidation (rusting). These finishes are expensive, particularly due to the environmental protection requirements which the plating process must comply with in the United States. However, the plating is soft and easily damaged in use. Also, it can be worn through where different parts of the carabiner rub together, such as the gate pivot area or between the threaded locking knob and the gate. Once the underlying steel is exposed, it may rust. This is most likely when exposed to corrosive environments which include such diverse things as chemicals in some industrial plants, acid rain, salt-water atmosphere and even sweaty hands. To protect carbon and alloy steel carabiners from rusting, clean and dry them after each use to remove dirt and moisture. Apply a generous amount of a good preservative, such as LPS1, to the entire gate surface including the cross-pins, gate pivoting area and under the locking knob. Inspect the body of the carabiner for damage to the plated finish and apply preservative there also, then wife off the excess from all of the carabiner’s exposed surfaces. We suggest LPS1 because it will penetrate into tiny spaces and get between steel surfaces and the moisture that attacks them. In normal use, stainless steel carabiners are usually free from the corrosion problems of those made from carbon and alloy steel. However, stainless steel is often chosen for use in harsh and corrosive environments. It is advisable to test any situation in which there is the possibility of unacceptable corrosive attack, in order to reassure yourself that the carabiner may be safely used for that application. Stainless steel carabiners should also be cleaned and dried after use to remove dirt and moisture. Apply LPS1 to the gate pivot area and locking knob threads for lubrication, then wipe off excess.