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Black Diamond Rocklock Screwgate Review

A great carabiner for heavy duty use like rappelling, belaying and top roping.
Black Diamond Rocklock Screwgate
Best Buy Award
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Price:  $12 List | $8.96 at Backcountry
Compare prices at 3 resellers
Pros:  Keylock nose, large gate opening, round stock for smooth belaying and rappelling
Cons:  Somewhat heavy, big
Manufacturer:   Black Diamond
By Ryan Huetter ⋅ Review Editor  ⋅  Nov 16, 2016
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#2 of 11
  • Function - 30% 8
  • Ease of Unlocking and Locking - 25% 8
  • Compactness lightweight - 20% 6
  • Gate Clearance - 15% 9
  • Gate Hang Up - 10% 8

The Skinny

Black Diamond's Rocklock carabiner is BD's largest locking carabiner and it is designed with belaying and rappelling in mind. It is a durable, affordable locking carabiner, and with a price of $11.95 it is our Best Buy Award winner. For climbers looking for a purpose-built carabiner 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 will prove a burden, and we recommend a lighter option for a belay carabiner like the Petzl Attache. The Rocklock locks shut with a standard screw closure. Of the larger sized carabiners reviewed, this was one of our favorites, but if you are looking to load up on small lockers we liked the Black Diamond Positron for its versatility and compactness. It is nice to have a locking carabiner that serves multiple functions, but if you are only looking for a locker to attach your belay device to your harness for single pitch or top rope applications, a belay-specific carabiner design like the Top Pick DMM Belay Master 2 can help you avoid cross loading your locker while belaying.

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Our Analysis and Test Results

Updated Version for 2016

Black Diamond made structural changes to the RockLock since we tested it:
  • Geometry — The shape of this carabiner has been altered! It now features a slightly more curved spine. The purpose of this is to maximize the size of the gate opening. We haven't tested this new version yet to see how much of a difference this makes. Be advised that the rest of this review reflect's last year's carbiner.

Hands-On Review

The Black Diamond Rocklock Styles

The Rocklock is available in three styles: screw gate, twist lock, and magnetron. Check out the side-by-side comparisons below, with the screw gate shown on the left ($12), the Twist Lock in the middle ($19), and the Magnetron ($25) on the right.
Black Diamond Rocklock
Black Diamond Rocklock Twist Lock
Black Diamond Rocklock Magnetron

Performance Comparison

The wide basket makes this one of the friendliest lockers to use a Munter hitch with.
The wide basket makes this one of the friendliest lockers to use a Munter hitch with.


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 this heavy stock, this locker also better resists the abrasion inherent in the high friction uses like belaying and rappelling than does a lighter weight carabiner such as the Black Diamond Vaporlock Magnetron. These carabiners are great choices for use on a top rope thanks to their low friction, thick material and ability to clip into bulky master points.

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 liked how smooth belaying with a Munter hitch was, thanks to the wide basket.

A well-managed multi-pitch anchor  high on the East Face of Whitney.
A well-managed multi-pitch anchor, high on the East Face of Whitney.

Ease of Locking and Unlocking

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 opened and shut smoothly in most situations, as long as it was not screwed tight too far in either direction. Some overzealous users screwed it open onto the stop ring a few times, and it was quite difficult to release it. When locked, the Rocklock stays locked, much better than on the lightweight Edelrid Pure Screw, but auto-locking carabiners like the Petzl Am'D Twist-Lock 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.

The large basket of the Rocklock makes creating clove hitches directly on the carabiner much easier.
The large basket of the Rocklock makes creating clove hitches directly on the carabiner much easier.


What the Rocklock Screwgate provides in function and overall versatility, it gives up in compactness and weight. It is the second heaviest locking carabiner in the review, behind the DMM Belay Master 2. 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.

This 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 a great choice.

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.
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.

Gate Clearance

The Rocklock Screwgate had one of the largest gate openings of the ten locking carabiners reviewed, alongside the Petzl Am'D Twist-Lock and Petzl Attache. A large 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 made 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 either a dedicated belay carabiner with a keeper gate like found on the Wild Country Ascent Lite Belay or simply a smaller locker, like the Black Diamond Positron Screwgate.

The Rocklock is big enough to accommodate clove hitching two ropes  nice when climbing on double rope systems.
The Rocklock is big enough to accommodate clove hitching two ropes, nice when climbing on double rope systems.

Gate Hang Up

The standard in carabiners has shifted away from notched noses toward keylock style, which has resulted in far less gate hang up. Black Diamond uses keylock noses on all of their locking carabiners, including the Rocklock Screwgate. The keylock nose allows us to more easily remove belay devices and ropes from the carabiner, especially when there is still some tension on the rope, and gives a smoother clip when clipping or unclipping the locker from bolt hangers.

With a massive opening and a keylock nose  the Rocklock is a favorite among belayers and rappellers.
With a massive opening and a keylock nose, the Rocklock is a favorite among belayers and rappellers.

Best Applications

This is Black Diamond's flagship belay carabiner, and it pairs perfectly with a tube-style belay device like an ATC or a Petzl Reverso. Its smooth handling and feeding of rope makes it a great choice for belaying and rappelling, in gym climbing, outdoor top roping, and big wall climbing applications. It is a little too big and heavy to recommend for long multi-pitch climbs where weight is an important consideration, or for situations where a smaller locker would do the job just as well. But for the budget-conscious climber who is looking for a durable addition to their harness, this contender is a solid performer.


At a retail price of $11.95, 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 the best bet. Lighter options like the Petzl Attache will perform all the same duties at a fraction of the weight but will cost a third more, not an insignificant number if you are buying six or eight lockers.


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, it wins our Best Buy Award and is recommended for most climbing situations.

Ryan Huetter