All About Locking Carabiners

All About Locking Carabiners

  • Posted by Kaleigh
  • On September 25, 2018
  • Comments

Take a seat. I think it’s time we had a talk…

I’m sure you have a lot of questions, and it’s only natural to be a little hesitant or curious. There can be a lot of confusion with how to smoothly operate, what things go where, and all the shapes, my god, all those beautiful shapes! But don’t you worry, I’m going tell you everything I know… about LOCKING CARABINERS!

Where to start?

Well first off, a locking carabiner is just a small loop of metal with a gate that opens and locks. What for? To securely lock things to us, silly! At first it was for things like straps or carbine rifles, but now things have gotten so much more… interesting! There are an endless number of shiny toys and devices and elaborate ropes and straps to connect with in an unlimited number of ways. It’s all very exciting! So, while a basic loop of metal with a gate opening used to suffice, now we have the freedom, the novelty, and the know-how to use just the right tool to get the job done. So sure, your giant HMS carabiner might do ok with your new assisted braking belay device or your lightweight D-Shaped carabiner might hold a tight clove hitch, but remember we’re going for exceptional, and size does matter!

Protection? Always! Safety is priority number one! Luckily, all lockers can be safely operated with the pretty minimal instruction (however, be sure to read your instruction manuals). While safety is most important, smooth operation and easy manipulation can really leave a lasting impression that brings you back for more.


« The basic SCREW-LOCK carabiners are a classic option.  You screw it to open and screw it shut… easy, reliable, dependable. The locker of the people, I like to say. It’s your most commonly found locker and, generally, the most affordable. Sure, you better not forget to check if you actually locked it, but you should do that anyway! Petzl conveniently has a red indicator for when the screw isn’t shut.

« Next, the automatic TWIST-LOCK carabiner is another smart choice. This thing needs to be twisted a quarter turn before it’s free to open up. With a little practice, this lock can be easily and quickly manipulated with just one hand. Preeetty slick.

« The TRIACT-LOCK carabiner takes three steps before you can open its gate. Now, I know that sounds like a lot, but the amount of protection this puppy packs is unparalleled. It takes a real aficionado to open this one up single handedly. Better start practicing, if you plan on whipping one of these out. You don’t want to look like a real gumby and spoil your new belaytionship.

« Lastly, the BALL-LOCK is a special one. This technically takes three steps also but flows together like a simple twist-lock carabiner. Push that button and twist a quarter turn and voilà! Safety and speed in one!

The triact-lock carabiner vs the screw-lock


Lockers come in all shapes and sizes, each one as beautiful as the next! While all beautiful, they each have unique characteristics and abilities that will prove quite useful when the time comes, and trust me, if you continue on this path, that time will come! I think this is easiest if I just give you a few examples (all the carabiners below are from Petzl):

From left to right: Attache (pear-shaped), Williams (pear-shaped), OK (oval-shaped), Am’D (ball-lock, d-shaped), Spirit (compact d-shaped), Frieno (asymmetric d-shaped), William (triact, asymmetric d-shape), and Sm’D (asymmetric d-shape).

« Small Pear-Shaped (HMS) locking carabiner:

The Attache is an example of a lightweight compact pear-shaped carabiner. Its design allows it to work as a light anchor point, for “Attache-ing” (get it!) ropes and hitches, similar to the large HMS, but its smaller lighter size gives it the versatility to shine in multiple areas, like attaching, rappelling, or with a tubular belay device.

« Large Pear-Shaped (HMS) locking carabiner:

The Williams is an example of a very large, pear-shaped locking carabiner. Its size and shape, especially that giant basket (the wide bottom part of a carabiner where items are hung from), is perfectly suited for connecting multiple ropes and devices or thicker ropes and hitches. A perfect master point!

« Oval Shaped locking carabiner:

The OK is an oval-shaped carabiner. Its oval shape allows for a well-balanced loading, in the center of the carabiner rather than along the spine. This balanced design works well with devices you want centered, evenly weighted, and just don’t want to shift around under load (such as pulleys and ascenders), making them very popular in the aiding realm of climbing. I use one for my belay device, and in either direction, whether you like the gate on the left or right, you’ll get the same smooth action!

« Compact D-Shaped locking carabiner:

The Spirit screw-lock is an ultra-lightweight, compact carabiner that easily loads the spine of the carabiner with its small d-shape. Its slim design will easily fit in any bolt-hole, piton, chain, or anchor oddity you may run across. Basically, it’s a perfect match for your PAS (personal anchor system). Oh, by the way, it’s pretty ideal for your GriGri too.

« Asymmetric D-Shaped locking carabiner:

The Sm’D is an almost perfect hybrid between a pear-shaped carabiner and a d-shaped carabiner. It’s essentially a d-shaped locker with a bigger basket. Talk about versatility! This has a large enough basket to accommodate hitches and multiple rope rappels but really shines as belay carabiner for tubular belay devices and assisted braking belay devices. The Sm’D could be used for about anything and do a pretty damn good job at it!

« Specialty/Professional Use carabiner:

Petzl’s Freino (pictured on the left or above, depending if you’re on desktop or mobile) is special. Are you special? Are you a professional? Do you like the best of the best? Do you like to make life easier? Do you like to work smarter, not harder? If so, this is why you buy the Freino. The Freino is shaped like the Sm’D locker, but with a smooth full stock design and has this funny looking hook on the outside (we’ll get to that later). The automatic twist-lock is ideal for experts, to be used with one hand quickly and efficiently while maintaining the highest levels of safety. That extra hook on the side… well until you needed to add more friction to your system, or needed to redirect your break strand, or god forbid had to lower your helpless second from a fully-weighted position when belaying from your anchor above… until you’ve had the pleasure, you may never fully understand the love a true professional feels for his Freino paired with a GriGri. This carabiner might give you sticker shock but for those of us who know, it’s worth is far greater than its price tag!

Well, what else? Aluminum or steel? I can tell you, if you’re running a lot of top-ropes, you may as well run a couple nice, heavy duty steel lockers unless you plan on replacing them pretty often. Maybe you want to keep your rope from getting that nasty black aluminum coating or maybe a steel locker could be nice for your belay device if that suits your fancy, but heck, my aluminum one is still looking pretty good after all these years.

Have I answer all your questions?  You look more confused than when I started. Don’t worry, you’ll do just fine. Just remember to lock it up tight, make smart choices and always, always double check your knot! If you have any questions about what carabiner is right for you, stop by our gear shop next time you’re at the gym!

The Petzl Connect Adjust lanyard

The Reverso 4 set up on guide mode

Clove hitch on a Spirit carabiner