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Black Diamond Rocklock Screwgate Review

A great carabiner for close to the ground use like rappelling, belaying and top roping
black diamond rocklock screwgate locking carabiner review
Black Diamond Rocklock Screwgate
Credit: Black Diamond
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Price:  $13 List
Manufacturer:   Black Diamond
By Andy Wellman ⋅ Senior Review Editor  ⋅  Jan 8, 2019
  • Overall Utility - 25% 7.0
  • Ease of Unlocking and Locking - 25% 6.0
  • Compactness and Weight - 20% 4.0
  • Gate Security - 20% 6.0
  • Gate Clearance - 10% 9.0

Our Verdict

The Black Diamond Rocklock Screwgate is BD's largest locking carabiner, designed with belaying and rappelling in mind. It is durable, affordable, and with a retail price, presents fantastic value. For climbers looking for a locker to use on gym climbs, top-roping days, or rappelling, the Rocklock is a good choice that won't break the bank. If you are getting high off the ground or far from the trailhead, however, its weight may prove burdensome, and for these uses we recommend a lighter option, such as our award winning Petzl Attache. As the largest locker in this review, there is a lot that the Rocklock can do, but trends these days are also moving toward lighter and more compact lockers, which can also do most of the same things, without the weight and bulk.
Large gate opening
Round stock for smooth belaying and rappelling
Large and heavy
Rattley cheap feeling screwgate closure

Our Analysis and Test Results

We tested the version of the Rocklock that includes a screw gate, which is the most affordable version of the Rocklock, but there are also two other gate options to choose from––Twistlock and Magnetron. While the Twistlock may cost a bit more, it also comes with the assurance that the gate cannot possibly be left unlocked unintentionally, and also cannot wiggle open with vibration. Those who don't mind spending more money but want a larger and more durable version of the Black Diamond Vaporlock Magnetron should also investigate the Rocklock Magnetron.

Performance Comparison

black diamond rocklock screwgate locking carabiner review - with its large capacity, the rocklock screwgate makes for an...
With its large capacity, the Rocklock screwgate makes for an excellent master point for an equalized anchor, as it is easily able to hold a clove hitch, as shown here, or even two!

Overall Utility

Black Diamond's Rocklock Screwgate is a solid performer in a variety of applications. It is a flagship locking carabiner in Black Diamond's lineup, and is frequently included in packages with belay devices like their ATC Belay Device. With a round, thick stock, the Rocklock is able to allow rope to feed smoothly through tube-style belay devices while still providing enough friction to safely arrest falls. Thanks to its heavy stock, this locker also better resists the abrasion inherent in the high friction uses like belaying and rappelling than lighter weight carabiners such as the Black Diamond Positron. The Rocklock is a great choice for use on a top rope thanks to its low friction, thick material and ability to clip into bulky masterpoints.

black diamond rocklock screwgate locking carabiner review - the large opening makes clipping multiple bight knots into the...
The large opening makes clipping multiple bight knots into the Rocklock quite easy.
Credit: Ryan Huetter

In multi-pitch climbing situations, the Rocklock holds clove hitches well, and will even easily accommodate clove hitching in with two ropes, a common scenario when climbing on twin or half rated ropes, or when climbing as a party of three. We also like how smooth belaying with a Munter hitch is, thanks to the wide basket. With the exception of its size and weight, we feel this locker not only performs well at its intended purpose, but is also fairly versatile.

Ease of Unlocking and Locking

We used this locking carabiner in many situations, from top roping to multipitch climbing, alpine rock climbing, and even canyoneering. We found that the Rocklock Screwgate opens and shuts smoothly in most situations, as long as it is not screwed tight too far in either direction. Some overzealous users screw it open onto the stop ring a few times, where it becomes quite difficult to release. When locked, the Rocklock stays locked, but auto-locking carabiners like the Edelrid HMS Bulletproof Triple FG will provide better ease of opening, and since they lock automatically can be a more secure choice in certain situations. We certainly do not advocate only using auto-locking carabiners for all of your climbing uses since they can be cumbersome to use, but for some things like on your belay device or at the end of your personal anchor system clipping into an climbing anchor, having the extra security of an auto-locker can be helpful.

black diamond rocklock screwgate locking carabiner review - in order to open or close the gate, you must screw or unscrew the...
In order to open or close the gate, you must screw or unscrew the blue locker shown here. We found it to be somewhat low quality, as it rubs and squeeks as you open or close it.

We noticed, as many online reviewers have pointed out, that the screwgate of this locker squeeks a lot as you spin it, and also seems to rub, not opening or closing very smoothly. While this shouldn't be a safety concern, it doesn't make us feel as if we are using, or purchasing, the very highest quality equipment, an odd thing to say for a piece of gear from Black Diamond.

Compactness and Weight

What the Rocklock Screwgate provides in function and overall versatility, it gives up in compactness and weight. It is among the heaviest locking carabiners in this review. This is not a carabiner you would want to carry half a dozen of up a long multi-pitch rock climb, unless it was a big wall style climb where the extra weight is worth the additional functionality at complicated and clustered anchors. The Rocklock is also massive; the largest of any that we tested. This bulkiness made us shy away from bringing it on most backcountry climbs, since we could almost bring two lightweight lockers for the same weight and size.

black diamond rocklock screwgate locking carabiner review - at 85g, this one weighs considerably more than any other hms style...
At 85g, this one weighs considerably more than any other HMS style pear biner we tested, making it a poor choice if weight, or compact size, is a primary concern.

There is obviously always going to be a tradeoff, for as we shift towards lighter construction and materials, we will sacrifice durability, so we feel that for someone looking to equip themselves with a locker for use with their belay/rappel device or wherever there might be a lot of friction occurring over the rope bearing surface of the carabiner, the Rocklock is still a good choice.

Gate Security

Screw gate lockers, as this one is, suffer when it comes to gate security for the simple reason that the user must remember to close them every single time, or they are rendered ineffective. It is surprising how often a screwgate carabiner can be left unlocked over the course of a long day on a big route. They are also somewhat prone to unlocking themselves over time, simply by the force of vibrations running through the carabiner allowing the gate to wiggle open. The way to solve this problem is to be sure to flip the locker at all times, so that gravity works to keep the gate closed if it should naturally loosen.

black diamond rocklock screwgate locking carabiner review - screw gates have the unfortunate disadvantage of occasionally coming...
Screw gates have the unfortunate disadvantage of occasionally coming open on their own due to the vibrations of the rope or being knocked against the rope helping the screw the loosen and slip downwards. Orienting them upside down, as shown here, prevents this from happening as gravity keeps the gate closed.

Gate Clearance

At 2.4cm, the Rocklock Screwgate has one of the largest gate openings of the eleven locking carabiners reviewed. Only the Petzl Attache has more, while the Edelrid HMS Bulletproof Triple FG has the same amount. A large amount of gate clearance is important when clipping into bulky master points on anchors, especially when they are made of thick diameter materials like static rope or are fixed sling anchors comprised of many pieces of material. The large gate opening on the Rocklock makes it easy to clip into the rope strands when setting up belay/rappel devices on the rope. When using a device that keeps the rope from interacting directly with the carabiner, like a Petzl Gri-Gri though, we found it easier to use a dedicated belay carabiner, such as the Petzl Freino.

black diamond rocklock screwgate locking carabiner review - we measured the open gate clearance at 2.4cm, which is a lot of...
We measured the open gate clearance at 2.4cm, which is a lot of space for sliding hitches or multiple items on and off easily.

black diamond rocklock screwgate locking carabiner review - high on the swiss arete of mount sill in the sierra nevada...
High on the Swiss Arete of Mount Sill in the Sierra Nevada, complicated multi-pitch anchors are made more manageable by using the right locking carabiner.
Credit: Ryan Huetter


The Black Diamond Rocklock Screwgate is not the least expensive of the locking carabiners we reviewed, but it is the most versatile and functional of the lower priced lockers. We feel that a new climber looking for a locking carabiner that will be a jack-of-all-trades at a budget price, the Rocklock is a great choice.

black diamond rocklock screwgate locking carabiner review - the rocklock makes a good choice for belaying of any type due to its...
The Rocklock makes a good choice for belaying of any type due to its large round stock construction that allows for smooth handling and minimal friction, as well as increased durability over I-beam construction.


If you are looking to start your basic climbing rack, the Rocklock Screwgate is a great choice to pair with your belay/rappel device, and your personal anchor system. With a simple and functional design at an economical price, we can recommend it for all situations where weight or size are not primary considerations.

Andy Wellman
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