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Locking Carabiners

All About Essential Climbing Equipment


Dennis Jump rappels off

Always use an auto-locking carabiner on your rappel device so it can never open and let the rope slip out.

Photograph © Stewart M. Green

Locking carabiners are an essential climbing safety tool when you’re rock climbing since their gates can be locked in the closed position to prevent the carabiner gate from accidently opening. Climbers use carabiners, metal snap-links made of aluminum or steel, every time they go rock climbing. Carabiners are the work horse of your climbing rack of equipment. Carabiners are used to connect all the different parts of the climbing safety system together.

Locking Carabiners Keep You Safe

Locking carabiners are an important part of your rack. You use carabiners to clip the rope into protection like cams and nuts, to tie together an anchor system for belaying, to tie yourself into an anchor, to fix the rope to an anchor for rappelling, and to attach the rope to an anchor for top-roping. Locking carabiners manage all these tasks safely and ease your mind in dangerous situations since you know that your rope and yourself are securely attached to the rock.

Two Types of Locking Carabiners

There are two types of locking carabiners: screw-gate carabiners and auto-locking carabiners. Each has its place on your rack. Locking carabiners come in three basic shapes: oval, D-shaped, and asymmetrical.

Screw-Gate Locking Carabiners

The screw-gate locking carabiner, the less expensive alternative, has a threaded collar which simply screws down over the gate so it cannot open. You twist the collar with your fingers to close and open the gate. Be careful not to over-tighten the screw collar or you may have a lot of difficulty unscrewing it to open the gate later. Screw-gate locking carabiners are the most common locking carabiners that you will use but they have their limitations. Screw-gate carabiners can come open. Sometimes the screw collar simply rubs against a rock surface and loosens enough for the gate to come open.

Auto-Locking Carabiners

Auto-locking carabiners are simply that—carabiners with a spring-loaded collar that automatically closes tight over the gate when you let go of it. Auto-lockers are more expensive than screw-gate carabiners but they are worth their weight in gold since they provide a much greater margin of safety than a screw-gate carabiner. That said, you don’t want to outfit your rack exclusively with auto-locking carabiners since they tend to be big and heavy. Use them only for essential climbing tasks and for an extra margin of safety when necessary.

When Should You Use a Locking Carabiner?

When should you use a screw-gate carabiner or an auto-locking carabiner? A rule of thumb is to always use an auto-locking carabiner for your personal safety and any time you rely on a single carabiner for your safety as when rappelling, belaying, and tying into an anchor.

Use a Locking Carabiner in These Situations

Here are some situations when you should use a locking carabiner:

  • For clipping yourself into a belay anchor (auto-locking carabiner preferable).
  • For clipping a daisy chain into any anchor (auto-locking carabiner preferable).
  • For attaching a belay device to your harness (auto-locking carabiner preferable).
  • For attaching a rappel device to your harness (auto-locking carabiner preferable).
  • For attaching yourself to a climbing rope at a gym (auto-locking carabiner preferable).
  • For attaching your rope to anchors for top-roping. Run your top-rope run through two carabiners (auto-locking carabiners preferable).
  • For clipping your rope onto your first piece of protection.


PETZL Locking Carabiners
BLACK DIAMOND Magnetron Locking Carabiner
CAMP USA Locking Carabiners
OMEGA PACIFIC Locking Carabiners
METOLIUS Locking Carabiners
ROCK EXOTICA Pirate Locking Carabiners
SMC Locking Carabiners

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