Petzl
Petzl Attache
"Iconic pear-shaped HMS locker for belaying — keylock nose, screw-gate, lightweight aluminium"
Best of 2026
Best Locking Carabiners
A locking carabiner is one of the most critical pieces of climbing safety gear. It connects your belay device to your harness, builds anchors, and secures rappel setups. The locking gate prevents accidental opening under load. We have reviewed the best locking carabiners for every climbing application.
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The picks
8 products reviewed
Black Diamond
Black Diamond RockLock Screwgate
"Workhorse pear-shaped locker — wide gate opening, smooth screw action, the de-facto belay carabiner in many gyms"
Petzl
Petzl Am'D Screw-Lock
"Asymmetric D-shape lockers for anchor building — high strength on the major axis, compact body"
Black Diamond
Black Diamond Magnetron RockLock
"Auto-locking via magnets — fast one-handed operation with no twist, great for guides and frequent use"
Mammut
Mammut Bionic Mythos Screwgate
"Lightweight pear-shaped HMS for sport climbing — smooth gate action and a clean keylock nose"
Edelrid
Edelrid Pure Screw
"Compact D-shape screwgate locker — affordable, durable, ideal for personal anchors and rope team setups"
Petzl
Petzl William
"Large pear-shaped HMS for Munter-hitch belaying and tied-off rappels — extra-wide rope-side basket"
DMM
DMM Belay Master 2
"Belay-specific HMS with plastic captive bar that prevents cross-loading — favourite of UK climbing instructors"
Guide
How to choose
How to Choose a Locking Carabiner
Locking mechanism is the key decision. Screwgate is simple and reliable. Auto-locking is faster but has more moving parts.
Key Types
Screwgate: A threaded sleeve you manually screw shut. Simple, reliable, and affordable. Requires you to remember to lock it.
Auto-Locking (Twist-Lock): Springs shut automatically when you release the gate. Faster to clip but can be harder to open one-handed.
Triple-Lock: Requires three actions to open (lift, twist, open). Maximum security for critical connections like belay setups.
Key Factors
Strength: Rated in kilonewtons (kN). Look for at least 20kN along the major axis. Most quality carabiners exceed this.
Gate Opening: Larger gate openings (20mm+) make it easier to clip ropes and gear. Important for belay carabiners.
Shape: HMS/pear-shaped carabiners work best with belay devices. D-shaped carabiners are stronger and lighter for anchors.
Weight: Ranges from 50g (ultralight) to 100g+. Matters more when carrying many on a trad rack.
Budget Guide
- Budget ($8-15): Basic screwgate carabiners — perfectly safe and functional
- Mid-range ($15-25): Auto-locking with smooth action from reputable brands
- Premium ($25+): Ultralight or specialised belay carabiners
FAQ
Common questions
If you belay, yes. Your locking carabiner connects the belay device to your harness — it is a critical safety link. Most climbers own at least two: one for belaying and one spare. They are inexpensive and last for years.
✦ More on carabiners
Reference, comparisons, picks.
✦ New to climbing?
Start with the guides.
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