Carabiner Questions and Answers

Carabiner Questions And Answers

Carabiner Questions and Answers

Carabiners are a type of connector used in rope access, rope rescue, and arborist work to join two pieces of equipment together. They go by many names including snap links, biners, and karabiners. They are available in a large number of styles and materials with various types of closing mechanisms.

We receive a lot of questions about carabiners and here are the answers to some of them. If you have additional questions please ask us in the space at the bottom of the page and we will answer them for you.

The first step is to determine how the carabiner will be used. Will it be used for lifting equipment or people? How much weight should it be expected to hold? What type of conditions will it be used in? Is it a dirty environment? Is it close to salt water (ocean)? These questions will help determine the most suitable carabiner design.

Aluminum carabiners are used worldwide every day for rescue use particularly where weight savings is a major concern such as mountain rescue. It is more important to make sure that the carabiner meets the proper strength requirements for the organization based on the intended use.

There are rumors that if an aluminum carabiner is dropped it can develop a ‘micro fracture’ in the aluminum which can cause it to fail. Numerous tests have show this is not true. If you drop an aluminum carabiner you should inspect if for proper function. If the gate still works properly and there is no visible damage, it is safe to continue using it. If the gate does not operate properly or there are still questions about it’s safety, we recommend to discontinue using it and destroy it to prevent accidental future use.

A carabiner is designed to be pulled between two points. Tests performed to determine the strength rating of the carabiner are performed in this way. When the carabiner is pulled in a way in which it was not designed it will result in a reduction of the rated strength. Three way loading refers to a carabiner being attached to three separate pieces of equipment each pulling the carabiner in a separate direction. This can result in a dramatic loss of strength and failure of the carabiner.

Aluminum does not rust but can suffer from galvanic corrosion. An aluminum carabiner often has parts such as pins made from steel. These dissimilar metals can react with each other causing corrosion which will damage the carabiner over time. Because of this, we recommend the use of stainless steel for use in or around salt water. Similar to diving equipment, after using equipment around salt water you should rinse it with fresh water to remove any salt residue from the metal and allow it to dry before storing it.
Oval carabiners hold a load centered between the spine and the gate. This is a compromise which results in a slightly weaker carabiner than a D-shape but gives the user more flexibility. Because an oval carabiner is symmetrical it doesn’t require the user to rotate it for the best orientation. This feature is very useful in tree climbing applications. An oval carabiner is also a great choice when webbing is used since the centered design suffers less strength reduction than a d-shape carabiner.

A <a href=”https://www.seaairthai.com/shop/?filter_shape=d-shape”>D-Shape carabiner</a> is designed to hold weight along the the strongest part of the carabiner, the spine, and away from the weakest part, the gate. This makes D-Shape carabiners the strongest available. D-Shape carabiners are a good choice for rigging and other options where strength is the most important concern.

An HMS carabiner is shaped similar to a pear and is larger on one side than the other. HMS carabiners are designed for use with belay knots such as a munters hitch. The design also allows for a larger gate opening than similar D-shape and oval shaped carabiners. Because of their multiple uses, HMS carabiners are great for rappelling and tactical applications.

We do not recommend carabiners without locking gates for rescue or work at height use. This is because of the possibility of the load accidentally ‘rolling out’ of the carabiner.

A screw lock was the first type of locking gate carabiner. We prefer the use of automatic locking gates but screw locks are better for some activities. If used in dirty environments a screw lock carabiner is more reliable than an autolocking carabiner. Screw lock carabiners are also useful for rigging since they can be left unlocked until after the rigging is complete and then locked.

It used to be taught to tighten a screw lock carabiner then unscrew it a small amount. This was done to prevent the gate from locking closed under weight. With newer better carabiner designs this is no longer a problem. A screw lock carabiner should be tighted all the way closed before use and not loosened until it is removed.

An autolocking carabiner gate uses a spring to lock automatically when the carabiner is closed. The main benefit of this type of carabiner is it lessens the chance of human error from the user leaving the carabiner unlocked. Auto locking carabiner gates are called by various names depending on the manufacturer including Auto-lock, Kwiklock, and Locksafe.

A two stage gate requires two motions to open it, usually a twist and push. A three stage gate requires three motions to open it, usually pull, twist, and push. Two stage gates are common in vertical rope access work where there is less of a chance of the gate rubbing on something causing it to open accidentally. Three stage gates are more secure but care should still be taken to prevent the gate from coming open accidentally.

While auto locking gates are more secure than many other types, they can still fail to lock properly. This is usually because of the locking mechanism getting dirt or other debris inside causing it to malfunction. In order to prevent this we recommend regular inspection and cleaning. To be safe, we recommend always gently squeezing a carabiner after it is connected to equipment to ensure the gate is locked properly.

The American National Standards Institute (ANSI) industrial fall protection standard Z359.12 includes carabiners as part of the standard. This standard requires the gate of the ANSI carabiner to withstand a direct force of 16kN (3500 lbf). The European EN 12275 standard requires the gate to withstand 2 kN of force and the EN 362 standard requires the gate to withstand 1 kN of force. The NFPA standard does not require this test.

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