Black Diamond RockLock Review — Our Biggest, Toughest Locker
A year on the rack, bought when we were learning double-rope technique
Comparing more than one carabiner? This is one of five in our full HMS carabiner comparison — see how the RockLock stacks up against the Petzl Attache, DMM Phantom HMS, Mammut Crag HMS, and AustriAlpin Rondo.
Read the full comparison →| Weight | 85 g |
|---|---|
| Shape | HMS (Pear), Type H connector — for the Munter hitch and every tube-style belay device |
| Gate Type | Screwgate sleeve, one-hand operable |
| Major Axis / Closed Gate Strength | 24 kN (5,395 lbf) |
| Minor Axis Strength | 7 kN |
| Open Gate Strength | 7 kN |
| Gate Opening | 21 mm |
| Materials | 95% aluminium (7075 & 6061, 25% pre-consumer recycled content), 4% steel, 1% Delrin |
| Country of Origin | Taiwan |
| Warranty | 2 years |
| Best For | Heaviest-duty locker in the lineup · anchor building · Munter-hitch belaying · racking gear |
Our Score
In This Review
Where to Buy the Black Diamond RockLock
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Why It’s Still on Our Rack
We picked this up a year ago alongside the DMM Phantom HMS, right when we were learning to climb on half ropes. We wanted a locker that could handle a Munter hitch cleanly if a belay device ever got dropped or fumbled mid-pitch.
The RockLock is the biggest, heaviest carabiner in our kit at 85g — and that size is the whole point. A wide 25mm gate opening and a pear-shaped HMS body swallow a stack of ropes, a belay device, and cold or gloved fingers without a fight.
Design & Build Quality
The keylock nose has never snagged on a bolt hanger or another biner in a year of use. The square hinge end does exactly what Black Diamond says it does, too — it keeps the belay loop sitting where it should instead of sliding around the basket.
The screwgate sleeve is genuinely one-hand operable, which matters when the other hand is holding a brake strand. The 25mm gate opening is unusually wide for an HMS, and Black Diamond credit a slightly curved spine for it — a small design choice you feel every time you clip a loaded anchor.
It’s made from 7075 and 6061 aluminium with 25% recycled content, rated to 24kN on the major axis and 8kN with the gate open. That’s plenty of margin for anchor building and belaying, which is what we use it for. As an everyday quickdraw carabiner it’s simply too big and heavy.
Pros & Cons
Pros
- HMS shape built for the Munter hitch and every tube-style belay device
- Keylock nose — no snagging in a year of use
- Square hinge end keeps the belay loop seated properly
- Screwgate sleeve is genuinely one-hand operable
- 25% recycled aluminium and a 2-year warranty
- 4.9 out of 5 from 157 reviews on Black Diamond’s own site
Cons
- Heaviest carabiner in our lineup at 85g
- Too big and bulky to double as an everyday quickdraw biner
- Manual screwgate only — needs discipline to check every time
Black Diamond RockLock Review: Final Verdict
A year in, this is still the carabiner we reach for when the job is anchor building or Munter-hitch belaying rather than quick clips — the size that makes it clumsy as an everyday biner is exactly what makes it excellent at the one job it’s built for.
If you want something lighter and more of an all-rounder for a first locker, our top pick for that role is the Petzl Attache, covered in our full HMS carabiner comparison.
Frequently Asked Questions
Is the Black Diamond RockLock good for a Munter hitch?
Yes — its HMS (pear) shape and wide 25mm gate opening are exactly what a Munter hitch needs, and it’s one of the reasons we picked it up when learning to climb on half ropes.
Is the RockLock too heavy for everyday clipping?
At 85g it’s the heaviest carabiner in our HMS lineup, so we don’t use it as a general-purpose quickdraw biner — it’s our pick specifically for anchors and belaying, where the extra size and strength margin are worth the weight.
Can you operate the RockLock’s screwgate with one hand?
Yes — the screwgate sleeve is genuinely one-hand operable, which matters in practice when your other hand is holding a brake strand.
What is the RockLock made of?
95% aluminium (a mix of 7075 and 6061, with 25% pre-consumer recycled content), plus 4% steel and 1% Delrin, per Black Diamond’s own spec.