Which Carabiner Do I Need?

Carabiners: one of the most widely-used tools in the arborist industry. Tree Climbers use them for all types of applications. Connecting into our climbing systems, setting up rigging configurations, storing gear on our persons, and more.

So depending on your climbing style, which types of carabiners do you need? With an abundance of carabiner options on the market, we are here to help you choose the right ones for your needs! Before I begin, the information contained within this blog is in accordance with the TREE CARE IN THE UNITED STATES. Please be aware that other "at height industries" and other countries have different carabiner regulations.

Carabiners Have Regulations??

That is correct! As with most industries, there are set rules and regulations to keep people safe. In our industry, carabiners (for life support purposes) must meet a kN rating of 22.24. One kN is equivalent to 224.808 lbs. but rounding up to 225 lbs. is a safe bet and simplifies things Generally, rounding up to 23kN is what most do and if you follow that, you’ll be solid.

Life support carabiners must also have a self-closing and self-double locking gate-locking mechanism that requires at least two consecutive, DELIBERATE actions to unlock. However, most (including myself) say that it must have three consecutive actions to be good and are as follows; push up on the gate, twist the gate and the third action is pushing the gate open. So, this means that screw gates, single push to open, and wire gates are not suitable for life support.

DMM Makes it Easy

DMM color codes their carabiner gates if you haven’t noticed by now. Purple is their signature quad lock. Green is triple action. Yellow is a screw gate, and the red means quick action.

Beware the ORCA Locks! Rock Exotica has created the ORCA Lock gate function for some of their carabiners. So, what’s the difference between the ORCA gate versus a traditional gate? Well, the ORCA can remain in the open position and if the user is not leery or is unaware of this feature, it could spell disaster!

Steel or Aluminum Carabiners?

Most people wonder what is the best carabiner material, steel or aluminum?

Both aluminum and steel can be used in life support situations, if they meet the appropriate criteria. It is good to match material with the same material, in other words, steel to steel and aluminum to aluminum. However, (and this will be controversial) I do mix and match for rigging. I’m always conscious of when I can apply these mixed items.

If corrosion popped into your head as you read that, you don't really need to stress over that issue unless you work around salt water or sweat profusely. Salt water does cause Galvanic Corrosion. Anodized carabiners have gone through a process to help against corrosion, but it doesn’t make them corrosion-proof. Don’t expect them to last long if they are continuously exposed to salt water. 

Determining Carabiner Strength

Most arborist carabiners will have three different ratings stamped onto the spine. There is a rating for the major axis (along the spine), the minor axis (sideways) and while open. You may also encounter an ANSI rated carabiner. ANSI rated carabiners will have a 16kN gate, which typically is used with fall arrest systems.

Understanding Carabiner Shapes

Oval carabiners are likely the most popular variety. They are also considered by some to be the OGs of carabiners. The Oval shape allows the climber to easily reorient the carabiner so that the gate faces the climber, and this is done for ease of clipping or unclipping from the climbing system. They are also preferable when using pulleys with fixed plates. If the fixed plate pulley is used with a D-shaped carabiner, when loaded the fixed pulley will shift towards the spine and can damage the side plate of the pulley. An oval-shaped carabiner will keep the fixed pulley in place with limited load shifting. A downside to an oval happens to be because of its shape. Because load does not shift towards the spine, the load is distributed between the gate and spine, making this the “weaker” of the bunch. This shouldn't disqualify oval carabiners from being used though, as they still can be quite functional.

D-shaped carabiners have a smaller gate opening than oval but are considered to be the strongest-shaped carabiners available. When the load is set into this style carabiner it gets shifted to the spine of the carabiner, which is the strongest part of the carabiner. There is another carabiner close to this shape and it is the Asymmetrical D-shape carabiner. These are fairly similar to the standard D; however, they are just a bit smaller in size and will actually have a larger gate opening.

Pear-shaped carabiners resemble that of an asymmetric D style but has a larger body toward the top of the gate. You may hear people refer to these as HMS carabiners and here’s a quick little fact; HMS is the abbreviation for the German term Halbmastwurfsicherung, and it means half clove hitch belay. So, with that bit of info there, that means this carabiner is meant to be used for belay applications. The top of the HMS carabiner is perfect for attaching multiple items. I’ve actually used this carabiner to connect two micro pulleys for some mechanical advantage when I was in a pinch, and it worked out perfectly!

Let the Application Choose Your Carabiner For You

When it comes down to choosing the best carabiner, the main factor is how you will use it. You may want to accomplish several functions, and in that case, you know you need several different carabiners to get the job done. You also want to be sure you properly take care of your carabiners once you start using them. Remember, Bartlett carries all types of arborist carabiners, stock up on what you need at Bartlett Arborist Supplies.