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. How to choose a carabiner? Looking at the type of use, combined with your personal preference, will help to narrow it down.
MATERIALS
The two primary materials used are Aluminum and Steel. Both are very strong but have very different uses primarily due to weight.
- Aviation Aluminum
Aviation aluminum is significantly lighter than steel and is therefore far more popular in the outdoor and climbing industries where weight is a major factor. For different containing elements, there are 7 series aluminum, 6 series aluminum. The best one is 7075, then the 6061 aluminum. To distinguish them you could test the strength and the hardness.
- Steel
Steel is used more commonly in the industrial industries due to its extreme strength and durability.
SHAPE MODIFIED
The modified D and pear have one side biger than the other to allow for more gate opening. These shapes are perhaps the most popular for all industries and are the preferred choice for use with a belay device.
- D SHAPE
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.
- OVAL
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.
- CAPTIVE EYE
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.
- OTHER SHAPES
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.
GATE TYPE
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
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!
- STRAIGHT GATE
The straight gate is the most common. The straight line across the opening tends to be a little stronger than a bent gate carabiner.
- BENT GATE
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.
- WIRE GATE
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 GATE
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.
- SCREW GATE
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.
- AUTO LOCKING
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.
- TRIPLE LOCKING
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
Strength is measured in kilo Newtons (kn) which is mass X acceleration. 1 kN is equivalent to 225 pounds. The minimum strength for most uses including rock climbing 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.
