Build My Own FeedQC LAB: Choosing the Right Tool for the Job - Carabiners
Before any piece of Black Diamond gear makes it on to the shelves, it spends months, sometimes years getting put through the wringer by our Director of Quality, Kolin Powick, and his team of Quality Assurance engineers. Through extensive and meticulous testing, both in the lab and in the field, KP and his team help ensure that you can count on your BD gear to be as durable, reliable and as strong as possible every time you head into the mountains or out to the crags. Our QC Lab posts aim to answer some of climbing's most common gear-related questions.
With dozens of companies making untold numbers of carabiners these days, it can be a real chore to navigate through countless different models to choose the one that's right for your type of climbing. Wiregate vs. standard gate. AutoLock vs. screwgate. Ultralight vs. heavy. What biners should I use on my slimmed-down alpine rack as opposed to my daily sport cragging kit? As with most pieces of climbing gear, there is a certain amount of inherent versatility, but often certain products are better suited, and more often than not designed specifically for certain applications. As with almost anything, it's always prudent to select the right tool for the job. This month we'll attempt to distill the basics of carabiner usage to help you figure out what's the right choice for your type of climbing.
Differences between Industrial and Recreational Carabiners
We'll start off with a quick word on basic carabiner use because we get this question all the time.
I get lots of random calls from arborists, fire departments, rescue workers, marinas, yachting folks, Jeep guys and warehouse personnel wanting to know if it's okay to use our carabiners for their particular application. The official answer is always no, not recommended. Just as all of our instructions say, our gear is "For Climbing and Mountaineering Only." But why?
The simple answer is that we are climbers and mountaineers, we know climbing and mountaineering, and we design, test and certify our gear for climbing and mountaineering. We're not as intimate with the loads, the uses, misuses and abuses of these other applications.
What many people may not realize is the different ways that recreational gear is designed, tested and rated compared to industrial equipment. Industrial carabiners are usually made of steel, are much heavier, are much stronger, and rated differently than aluminum climbing carabiners.
An industrial carabiner is usually rated to a SWL (safe working load, or safe working limit)- of let's say 30kN. This means that you can load the carabiner safely to 30kN. And in industrial applications there is almost always some kind of safety factor say of 2 or greater, which means that the carabiner won't actually break until around 60kN. However, climbing gear is rated to the load at which it will actually break. So a 20kN carabiner actually breaks at that load. There's a big difference.
Bottom line: Climbing gear shouldn't be used in industrial applications—it just isn't designed and rated for those types of loads and situations.
A Word About Strength
As far as carabiner "strength" is concerned, almost every carabiner available today is CE certified. This means they meet minimum strength requirements. A bunch of smart people have spent a lot of time determining what these standards should be, given real-world climbing and mountaineering loading scenarios. There are some subtle differences and exceptions when getting into the nitty gritty of different kinds of carabiners, but for argument's sake, the minimum strength requirements for most climbing carabiners are:
Closed gate strength - 20kN
Open gate - 7kN
Minor axis - 7kN
Though in theory loads at the belay can reach 20kN, this is extremely rare and likely caused because something didn't go right. Is a 24kN carabiner stronger than a 20kN carabiner? Yes. Does it matter? In most cases, likely not.
Now open-gate and minor-axis strengths for most carabiners are much less (about a third) than closed-gate, and are in the ranges that can actually be seen in the field. So a higher open-gate or minor-axis rating isn't necessarily a bad thing, but once again, all biners sold are going to meet the minimum requirements.
Choosing the Right Carabiner for Your Climbing
Even within the climbing and mountaineering carabiner world, how do you know which model or style to choose? Black Diamond alone manufactures over 30 different styles of carabiners. From belay-specific biners, lockers, wiregates, keylock and traditional-gate biners, to biners with "hoods" and now even carabiners with magnets. How is someone to know what is the right tool for the job? I'll speak mainly to Black Diamond's offering of carabiners because that's what I use and know best.
Belay Biners
Belay biners, also known as HMS biners, are always lockers, and typically have a large basket end to accommodate using a Münter hitch. There are heavier, larger versions usually made from a larger diameter rodstock, and there are smaller, often lighter versions which usually have a more aggressive I-beam construction-this puts material where it is needed to attain the required strength, but removes excess material from where it is not needed, resulting in a lighter biner. Larger diameter carabiners usually last longer as there is a consistent, larger rope-bearing surface to wear evenly, whereas lighter I-beam carabiners tend to show signs of rope wear more quickly due to the geometric differences where the rope runs.
I like the Rocklock or MiniPearabiner for my standard workhorse Belay biner, a Gridlock for use with a GriGri, and a Vaporlock for multipitch rock, ice or in the alpine.
Lockers
There are several different types of locking mechanisms available on the market today. As far as Black Diamond carabiners are concerned, these include:
- Screwgate
- TwistLock
- the new Magnetron
TwistLock and Magnetron biners are auto-lockers. Basically if the gate is closed, the mechanism automatically engages and it's locked, whereas a screwgate needs to be manually screwed shut to engage the locking mechanism. Screwgate biners are typically lighter than auto-locking lockers. Here you need to make a choice between less weight and added security.
As well as the different types of locking mechanisms described above, there are two general families of lockers: big and small. Typically large lockers are used for belaying (as stated above), setting up top ropes, or acting as the power point in anchors. Smaller lockers are often used to build anchors, on a particular placement where you could be concerned about the gate opening, or to clove yourself into an anchor.
Wiregate vs Non-Wiregate
In 1995, Black Diamond brought wiregate technology to the climbing industry with the HotWire carabiner. Wiregate carabiners are typically lighter, less susceptible to freezing, and because of the reduced mass, less susceptible to gate whiplash. During a climbing fall there is a lot going on-carabiners are getting loaded, ropes are stretching and getting tight, things are bouncing around. Traditional gates on carabiners have more mass to them, and during all of this bouncing and vibration, it has been shown that the mass of the gate can allow it to open slightly which in effect results in an 'open gate' loading scenario. And as stated above, carabiners are typically 3 to 4 times as strong when the gate is closed. The reduced mass of a wiregate carbiner alleviates this.
Personally I like the fact that wiregate biners are usually lighter and less susceptible to freezing so I typically use them for long routes with long approaches, and ice or alpine climbing.
Keylock Gate vs. Non-Keylock Gate
Carabiners historically used a 'hook and pin' configuration to allow the gate to interface with the body of the biner and give it its strength during closed-gate loading. This style is consistent, strong, relatively easy to manufacture and relatively cheap.
Another solid gate design came on the scene several years ago-the keylock gate. This uses the geometry of the pocket of the gate to interface with the 'nose' of the carabiner to provide its strength in closed gate. The advantage of this design is that it alleviates the chance of the hooked part of the carabiner to get hung up on something (like a bolt hanger, Stopper wire or sling). Nose hooked carabiners are surprisingly weak, and it's by far the most common scenario for carabiner failure in the field. Check out an old QC Lab post on the subject HERE.
The manufacturing process for making keylock gates is slightly more expensive, but you gain the benefit of a snag-free carabiner.
Until recently, if you were the type of person that really liked the snag-free keylock design, but also the lighter weight and no whiplash of the wiregate, you had to make a choice. But now BD's HoodWire Technology kills two birds with one stone. You get the functionality of a wiregate carabiner as well as the snag-free benefits of a keylock thanks to the carabiners simple wire hood. HoodWire Technology is available on both the HoodWire carabiner, as well as our updated Oz carabiner.
Heavy vs. Light
When our Oz carabiner first came out, my buddy Travis called me up all excited, "I'm going to order a full set of Oz quickdraws for my new sport climbing kit. They're so light!" It's true the Oz is a super-light biner at one ounce (hence the name), but is it the right choice for your sport climbing draws? Sure, if you're doing a multipitch sport route in the Canadian Rockies, or going for a hard, 22-draw onsight, go for it. But for a workhorse sport climbing carabiner, it's probably not the best choice. Why? In order to get the weight out of these lightweight biners, manufacturers are removing material, and though ultimately all carabiners are strong and meet all CE requirements, less material can mean a few things. The smaller size makes is slightly harder to clip. There can be less material in the spine, which makes it more susceptible to bending if loaded over an edge, and there oftentimes is less material on the rope-bearing surface, which means whippers are harder on your rope.
A quickdraw that is more optimized for daily cragging would likely have a snagfree carabiner on the top so it doesn't get up on bolt hangers, and a nice large biner on the bottom for ease of clipping. Something like the sport climbing specific Livewire Quickdraw, Nitron Quickdraw or Hoodwire Quickdraw.
We headed down to the drop tower to do a quick comparison of a few different manufacturer's workhorse-type biners side-by-side with several different lightweight rigs. The intent was to determine how many gnarly factor-1.7 drops, with a static belay, without moving the rope at all, would it take to trash a rope or trash the biner.
For most of the larger, heavier biners, the rope actually eventually ended up cutting, and the biner was still in good enough shape to throw on your rack and keep climbing. Whereas with the lightweight, smaller biners, after anywhere from 3-5 drops, the biner was severely deformed and was what I would consider non-functional (gate wouldn't open), and on a few occasions, the 10mm Dynex sling eventually cut.
Obviously this test is brutally harsh-no one in their right mind would (or could) take repeated gnarly fall factor-1.7 whippers with a static belay onto the same section of rope—but comparatively speaking, the lightweight biners got thrashed earlier. What's the moral of this story? Use the right tool for the job. Heavier biners with a greater cross section have their place as they are burly and can take abuse. Use something like this for your daily cragging quickdraws where you're more likely to fall repeatedly working the moves on your big proj. Whereas the smaller sized, lightweight biners aren't designed to withstand the same level of abuse and are more appropriate when weight is a concern, and you're not as likely to be taking huge lobbers repeatedly, like in the alpine, or when ice climbing.
Bottom Line
Of course any rated carabiner can be used for multiple purposes, but like most climbing gear, they are often designed for a specific or intended use. Choosing the right biners for the type of climbing you're doing will benefit you in the end-a rack of light wiregates on an alpine route will help you move faster, burly sport climbing biners will extend the life of your gear, etc. As with almost anything, it pays to have the right tool for the job.
Stay safe out there,
KP
United States / English 
16 Aug 2012, 9:11PM
Thanks guys, and thanks Eli for the additional detail!
8 Aug 2012, 9:36AM
Great article Kolin!
I have had this discussion with people more than a few times after they suggest using climbing equipment to pull a tree down or tow a car out of a ditch. Thanks for sharing your insight and expertise.
Before I began serving as a full time guide with the non-profit organization I am with, I spent 17 yrs working as a manufacturing engineer and equipment designer/prototype builder. I really appreciate all that you guys do to make, what we consider the best products in the industry. I won’t bore you with our BD inventory but we use your equipment all the time and have never been disappointed. Keep up the high standards…at any cost!
Thanks - Norm
7 Aug 2012, 7:46PM
Good, common-sense (?!) advice.
Your comments re: Rated Strengths in climbing gear are useful. I hope y'all will be attending the Access Fund bolting seminar in November. We need an engineering foundation for arguing the toss!
Bolts seem to provide a worst-case scenario for repeated use and seem to indicate a solid "safety margin" over an "ultimate strength" guideline.
Are we ready for a US standard?
Thanks Rusty
7 Aug 2012, 5:05PM
Is there a downlowdable .pdf version of this interesting article ?
Thak You
7 Aug 2012, 2:56PM
As usual, great stuff!
On a small note, I’d like to comment on a section of your article. Please understand that I do not represent any particular company, and simply offer my perspective from years in the industrial and recreational industry.
The section I’m commenting on is as follows:
“An industrial carabiner is usually rated to a SWL (safe working load, or safe working limit)- of let's say 30kN. This means that you can load the carabiner safely to 30kN. And in industrial applications there is almost always some kind of safety factor say of 2 or greater, which means that the carabiner won't actually break until around 60kN. However, climbing gear is rated to the load at which it will actually break. So a 20kN carabiner actually breaks at that load. There's a big difference.
Bottom line: Climbing gear shouldn't be used in industrial applications—it just isn't designed and rated for those types of loads and situations.”
I often find that there is confusion between all of those who work and play at height. Ultimately, regardless of whether we fall into the recreational, industrial, or emergency field, we’re all trying to accomplish the same task - keep workers safe at height. I could certainly spend page after page explaining the similarities between our three disciplines; but for the sake of all involved, I’ll simply try and clarify a few points; of course, feel free to email if you have any questions.
First, understand that Safe Working Load (SWL) and Working Load Limit (WLL) are one in the same. In fact, a number of years ago IRATA decided to drop the use of SWL and use only WLL to help with consistency (see attached document).
Regardless of what industry we're in (be it Industrial Rescue, Rope Access, Recreational, etc...), the end goal is the same - to insure the life safety equipment we're using has a safety factor built into it. The majority of equipment out on the market use the two following terms to delineate the working strength of the equipment: Working Load Limit (WLL) and Maximum Breaking Strength (MBS).
The WLL is calculated using an agreed upon industry consensus safety factor.
For instance, in the fire rescue industry, the NFPA uses a 15:1 safety factor. Thus a rope that has a MBS of 5,000 lbs would have a WLL of 330 lbs. A rope with a 10,000 lbs MBS would have a WLL of 660 lbs - thus the reason 12.5 mm rope is used for two person loads during a rescue.
The recreational world (climbing, mountaineering, challenge courses, etc...) uses a 10:1 ratio.
And, the industrial lifting world uses approximately a 5:1 ratio. (Wire rope - 3.5:1, Chain - 4:1, Synthetic Straps 5:1)
Now, here's the confusing part. OSHA doesn't use WLL in their regulations. Instead, they reference a maximum user weight and allowable force on the body. It's another story for another day, however, OSHA sets a limit of 330 lbs for fall arrest equipment with an 1800 lbs maxiumum arrest limit. In addition, with some exceptions, all equipment must be rated to 5,000 lbs. Even though OSHA doesn't reference the WLL, if we do the math, we can see that a 15:1 safety factor exists (5,000 lbs / 330 lbs = 15:1). OSHA's reasoning is derived from their focus on the dynamic load that could be applied, not with the possible static load applied to a system. All the OSHA compliant fall arrest systems are tested assuming a maximum user load of 330 lbs.
So, to sum up, when industry references a 2:1 margin of safety, it is in reference to the Maximum Arrest Force and not a working load. So it is incorrect to assume a carabiner that has 30 kn written on it can actually withstand 60 kn before breaking. The long story short is that indeed your locking carabiners do meet OSHA regulations and can indeed be used for industrial work. However, they certainly wouldn’t last as long as industrial specific carabiners simply because they’re thinner, etc... So, you’re right in suggesting your equipment isn’t appropriate for industrial use. To cite one example however, PETZLs light weight lockers are used daily around the world within Industrial Rope Access.
To keep this email on the short side, I’m not diving into the emergency world, however, it’s all pretty basic. The only real show stopper is the fact that your equipment isn’t NFPA certified; Other then that, your carabiners do indeed meet the NFPA light duty rating.
Hopeful this all makes sense. As someone who has been intimately involved within all three disciplines (recreational, industrial, emergency), I’ve always been interested in trying to bridge the gap and improve our understanding of the regulations and standards that govern how and when we use equipment to protect us at height.
I hope this helps... Anymore questions?
Eli
7 Aug 2012, 1:03PM
Thanks so much for this. I am still very much on the newer side of climbing, and this report helped to answer some burning questions of mine. It rules, and your efforts are appreciated for sure. THANK YOU!
7 Aug 2012, 11:38AM
My favorite draw is a custom draw made up of a keylock straight gate biner on top, vari-width dog-bone, hoodwire on the bottom. The top can't be mistaken for the rope side because of the solid gate and won't snag on bolt hangers. The vari-width dog bones come in all different sizes are won't twist like the skinny dyneema ones, and the hoodwire is is perfect for clipping and won't snag while unclipping the rope.