MBS (Minimum Breaking Strength) on Climbing Gear is a Myth

MBS or minimum breaking strength is great for comparing one product to another and I appreciate having standards on life supporting gear, BUT to boil down a piece of gear to only 1 single number doesn’t tell the whole story and we discuss gear, their ratings and value and limits of backyard science.
MBS is Minimum Breaking Strength and usually printed or stamped onto most gear and is 3 break tests calculated with a 3-sigma rating means that 99.9% of the products are stronger than the reported MBS rating. If you calculated the average, then 50% of everything would break below that MBS number. 3 sigma ratings more accurately represents a product’s strength….. AS LONG AS YOU USE IT LIKE THEY TESTED IT
That is how MBS is calculated, but how is the gear tested. Short answer is idk: most of us don’t know. I do know ropes are usually done with larger diverters to preserve the strength since knots give such a variety of results. I do know that carabiners are usually pulled at a specific speed with a 10mm pin. But a lot of the standards are either boring af and/or behind a paywall. I appreciate standards and the committees that make them. Standards help us compare one product to another as fairly as possible. However, my backyard science isn’t doing standards but how I have personally used the gear or have seen it used, whether or not it was according to the recommended use. I like my kind of science.
So last year, I made a video about CMI hangers where I tested them in shear by bolting them down to concrete and got 34kn in all three of our tests or around 7,700lbf and not 10,000. My delivery of that video was unprofessional so i took it down.
But now I’m even more curious why they broke below 10,000lbs since they told me they did a lot of tests, that it meets standards and a 3rd party also messaged me and said they also did a lot of tests and it always broke above 10,000lbs. Now, no one was telling me the CONTEXT of HOW it was tested which I feel would be helpful since I’m guessing over here. No I’m not paying for and reading the UIAA and CE standards. I try to test gear in the way you and I use it so we understand it better, I’m not trying to replicate an already rigorous and thorough process. I attached it to the ground like I thought it was intended to be used, since I have seen numerous real world applications of it being attached to rock and being pulled in shear. However, the CMI company has specialized towards the arborist industry and these hangers are intended to be put in trees and pulled straight out, or tension or axial, rather than shear.
CMI HANGERS IN TREE
We tested these in a tree since that is how they are intended to be used.
***In shear we got 30.48 before bolt sheared off but hanger started to tear,
***42.74 tension when my puller got damaged and again at 42kn before bolt pulled out
***Another one in tension pulled out at 42.48 and started to tear the hanger.
***So a few conclusions: 1 - it doesn’t matter if a ⅝” bolt comes out first and 2 - pulling in shear is putting all the force on one side. Tension pulls on both sides more evenly.
CMI HANGER IN SLACKSNAP
In our SlackSnap or slow pull machine, we got 37.30kN with a quicklink and 48.44kN with a large shackle. We found the larger shackle got us 10,000lbf which is the clue to how they achieve 10,000lbf.
The CMI’s website is found at cmigearusa.com/products/bhang...
OUR CUSTOM 6mm THICK 316L STAINLESS HANGER - (Thank you Rune from Norway)
***Using a ⅜” Titan HD concrete screw in granite, the bolt sheared off at 46kN both times
***In Slacksnap machine, we got 65.20KN
***Conclusion: The smaller shape AND the different type of steel helped get an 20kn.
MONSTER CRUXES broke at the weld lower than 60kn
WAVE BOLTS broke around what they state, but they break lower also
FIXE HELY most broke above 28kn but some at 27kn
KNOTS break at 50% of MBS
CONCLUSION
No single breaking strength number can give you everything you could know about your gear, but it kinda gives you all you “need” to know. Super good enough. So be nice to gear companies so they don’t hate me, realize only knowing MBS is a limited understanding of your gear, and subscribe so you can see future videos of us testing things with backyard science. I’m amazed you read all of that!
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00:00 MBS is a Myth
05:45 Load cells are accurate
06:44 Testing CMI hangers in a tree
11:51 Testing CMI hangers in SlackSnap
15:40 Testing custom SS 6mm hangers
18:11 Conclusions
19:07 Other things break below MBS

[@HowNOT2]

Check out our new store! hownot2.store/

[@bkuker]

Anyone unwilling to share how they got their measured MBS has no right to complain, imo. Then your numbers, lower or higher, add value by showing people how it actually performs in different use cases.

[@miles11we]

I'm pretty sure they are contractually obligated (with the test organization) to not share that info, which is bullshit.

[@bkuker]

@@miles11we You're right, it's 110% bullshit. I don't doubt that their methodologies are sound and well engineered, but this is why these videos are so valuable in parallel to the manufacturers' specs. I would not risk my life on an unrated piece of gear from the hardware store just because it looks strong on the SlackSnap. I'd also want to see how rated gear performs in real world scenarios (including "misuse") before I used it, and I get that here!

[@mytech6779]

@@miles11we If they were using a standard test they could still give the test code number and the parameters and modifications used for it.

[@11378902]

"It's rated to 44kN under our testing specifications" "It keeps breaking lower, what are your testing specifications?" "We can't tell you. But it's rated to 44kN!.................

[@lepsycho3691]

Yeah, I don't understand why the parameters of the testing are not stated clearly. If the point is to standardise a breaking point, then they have to have a common ground in testing otherwise those numbers are meaningless (or it's marketing). I can understand shopvac saying it's vacuum is 4hp even though it's not true, but for life depending equipment, that makes no sense.

[@Aljonone1]

It means will take 44kN BUT less if shock load!

[@SentientTent]

@@Aljonone1 shouldn't just about anything take more force for a shock load? With shock load you have a finite amount of energy that can be dispersed through deformation. I just don't see how a force of 44kN for 0.05 seconds would break something but 44kN for 60 seconds wouldn't.

[@vesuviateresearches1504]

@@SentientTent the typical problem with shock-load is that it causes higher forces than expected. But yes, metals typically break at higher stress the faster it is pulled.

[@SentientTent]

@@ev6558 I guess I was considering a shock load to be an impact loading rather than I guess a static shock load where the force time graph is just a step function. But I don't think there would be really much of a difference in material strength between statically loading 44kn vs ramping up to 44kn. Except of course if the gradual rampup on loading is on a slow enough timescale that material creep starts to become a factor. I guess there's also the thing where if you put a 4,500 kg weight on something and it breaks you don't have any idea if it would have broken with a 3000kg weight.

[@NickCohn]

I work in IT security. This reminds me a lot of the discussions we often have with developers and people responsible for applications. We say 'if we do this it breaks your app', they respond with 'yes but, no one will ever do that' - well then you better make sure that the bad guys also know 'not' to do that. You can never control how your product is used, only how your product responds to any use scenario.

[@MrAM4D3U5]

Any vendor still preaching security by obscurity does not deserve to have any contract with any company.

[@Anodoin]

I've been in that situation and they told me to not do that. Made me want to throw a table.

[@redslime6390]

Unfortunately, unlike software, real things are affected by the laws of physics. You can't just go and make your product worse for the intended application because someone is using it wrong.

[@AssassinAgent]

My rule is: if it has a way to be broken, someone will absolutely break it. Doesn't matter if it is on hardware or software.

[@Troggination]

look man, if a company is saying something has an MBS that it doesn't reach under conditions that they specify (lag screw) and they won't tell you their exact testing methods, they should probably be thrown under the bus. you're a product reviewer, you reviewed their product, and gave it a bad review because it was bad.

[@jacktrussler20]

Couldn't agree more with this statement - if they're not being transparent I wouldn't want to trust my life to their equipment. Thank you for highlighting this company.

[@LoveAndClimbing]

There's a little nuance: the product itself is fine--the company just isn't describing it in an accurate and useful way.

[@SveinOlavGlesaaenNyberg]

@@LoveAndClimbing, true enough, but will the companies learn from this to make their description accurate? If they do, more honour to them. If not, then no.

[@michaelbrowder1759]

You are very fair. Don't worry about upsetting any company. I have no ax to grind with any company and agree they are all safe enough, but still your results are your results.

[@cmonkey525]

Well, the fact he pulled the video down makes me think the CMI lawyers sent Ryan some sort of letter. That and the fact that there's parts of this video that feel very scripted by maybe his own lawyer

[@QuietLifeintheForest]

I’m an arborist (and subscriber, love your channel) and it looks like (could be wrong) that you used a softwood tree. I’d run the test again on a hardwood tree to get well over 44kN. Also, while it’s designed for a lag, that practice is quickly being replaced industry wide with all-thread rods through the tree with washers and nuts. Wayyyyy stronger. Also also, that’s quite bad for the tree, almost painful to watch. Call a local tree company and ask if they have any removals scheduled of live trees you can experiment on first. You’d be able to test this on an already doomed tree.

[@SK-fo3hk]

Ryan sorry you have to deal with the schmucks at cmi. When I was working as a rep for a climbing distributor cmi was always a headache. While I like their pulleys and some of their gear I avoid them because they are truly ill tempered egos that really don't like to work with people. Looking for other options and I'm definitely psyched to investigate these other hangers since they are stronger and made by humans. Thanks for all of your work to demonstrate the continuing poor attitudes and defensiveness at cmi, and the realities of gear tests to allow us to make better and more appropriate decisions. You work is super good enough!

[@wileecoyoti]

I am in the sciences and love your channel! One of the most important lessons in this video is that by not describing the testing methods in paperwork provided with the product there's very little chance that anyone uses them the way that would get full strength. I see this all the time I'm engineering, where "how we tested" is practically irrelevant because it how folks actually use a product. Easy example: waterproof ratings are pretty much nonsensical because anything sealed builds vacuum and pressure as temperatures change. A "30m" depth rated watch is actually barely splash proof in many real life situations.

[@wcakgilleran]

I'm an arborist who has installed a ton of lag bolts in trees and I am super surprised that your getting so much strength from the threads on the lag biting into the tree. I'm glad to know what kind of forces are involved when trees pull lags out on their own. My boss used to say you're only as strong as your weakest link which we all assumed were the threads of the lag. For what it's worth in 23 years of being a climbing arborist (and a rock climber) I've never heard of using those hangers being used for anything except rock climbing. I could see their use in heavy logging where connecting cables to a winch for pulling would be convenient although I've never seen or heard about it....

[@teabee44]

People/ companies don't like when being called out, especially when their products don't perform as advertised.

[@LoveAndClimbing]

Ryan, while I appreciate your professionalism here, I have very little sympathy for companies if your channel hurts their business. They call it "minimum breaking strength" and put all the details of the testing standards behind a paywall, so it's entirely reasonable to interpret that as a claim that their gear won't break below the given amount of force. If it breaks at below MBS and they don't want that to be seen as them being caught in a lie, then maybe they should communicate their claims better. I think we can all agree that the gear is super good enough, but companies honestly and meaningfully describing the strength of their gear could use some improvement.

[@nickhardman9462]

21:50 To nerd out a bit, the cyclic loading/work hardening doesn't necessarily make it stronger, it makes it harder and harder generally means more brittle. (material dependent)

[@mytech6779]

It makes the material stronger but also thinner so overall strength is no higher. And yes also issues with fatigue cracking and reduced energy absorption.

[@kylemills8816]

I had to stop this video around 5:14, rewind, and pause- I set that bolt! I had NO IDEA that the intended use of those hangers were for arborist rigging, which is especially disconcerting since I was in a bind and needed hangers immediately, so I drove 45 minutes from where I live to the CMI factory and asked for hangers to use in a cave! Super good enough for what I ended up using them for, and wow, I can't believe those lag bolts held that well in a tree! I wonder if setting them in a hardwood like an oak would yield higher results...

[@rickjames8317]

Larry's the best! Man must be a saint to allow you to do all this on his property. The patron saint of bolt busters. Thanks Larry!

[@adrianmilitaru4967]

Seriously, normally you get shit for drilling one tiny hole in a wall. Ryan is massacring Larry's property in comparison

[@menriquez89]

They kind of fucked his tre. he obviously wanted them to stop but felt pressured to let him do one more.

[@JustinVodden]

I bet if the holes are drilled out larger, and dowls pounded in and sealed up, that tree will continue to thrive.

[@danieljensen2626]

Kinda whack that they won't tell you how to reproduce their tests. It's fine if there are a lot of factors that affect the results, but in that case it's sort of useless to quote results without a detailed method on how those results were produced. And if they're worried about people getting lower results (that are still super good enough), they should just low-ball the number in the first place.

[@SK-fo3hk]

Totally agree. Some self proclaimed proprietary knowledge is useful for maintaining relationships with the consumers.

[@Ivan.Wright]

Your last statement enrages almost any marketing team lol

[@beauthetford7608]

as an engineer I always think about yield strength and ultimate tensile strength (UTS) of materials. That max force your getting on your meters is the UTS; I'm thinking that the MBS is the average UTS they see, minus 3 standard devs. It would be smart (i think) if the standard dev came from a whole range of different loading scenarios: different pull directions, different impluses, etc. That would shrink the MBS down to the least bullshit value. If they're only testing one loading direction over and over and using the standard dev of those tests, that wouldn't be very realistic. You can't decide what direction to load a bolt when shit hits the fan.

[@SveinOlavGlesaaenNyberg]

Just a statistician disagreeing with the std deviation. They should not mix, but rather either: A. measure each situation and provide mean and std Or B. Supply the mean and the std deviation for the worst scenario. Doing means and std for different scenarios will lift their numbers, and the worst case scenario is after all not an outlier but (it seems) the very scenario we will be facing and putting our lives at stake in. And especially, if they call it MINIMUM Breaking Strength, they have really promised to address the worst case scenario.

[@beauthetford7608]

@@SveinOlavGlesaaenNyberg good point, you're saying if they tested a range of different loading scenarios as a single dataset, the worst case outcomes would be outliers and wouldn't contribute to the mean and sdev very much? Maybe testing a range of scenarios to first identify the worst case, to then test that scenario many times and base the mbs on only that data would be te way to go. This doesn't seem like a problem you could "overengineer", I'd be willing to pay for a bit more metal! So it wouldn't work even if we had the same number of observations for each scenario? I was thinking that would lead to a realistic mbs. Thanks for your input!

[@markp8295]

Great idea. If I ever form a climbing gear company, I will be adding an LBV to the products. Love the term. (Sadly the chances of me doing that are basically zero. I make my own Knuts for personal use and that's about it.)

[@purple0burtle]

I'm very surprised at the strength of the tree, to be honest. I can't believe that the drilled hole for the lag screw, managed to hold the screw, and therefore the fixing, for so long! Amazing the strength of wood!

[@benborsa8266]

Haha sounds like someone might have been threatened with a lawsuit. Haha solid video. Good info. As for how the weather affects, i would assume extreme cold is what they are refereing to.

[@crazedvidmaker]

I just have to be super overscrupulous about statistics here. It's a common misconception that "3 sigma" means that 99.7% of the things will break at a higher force (0.3% break at lower force). This is not the case. This number is generated assuming a gaussian distribution, and in this circumstance, and many others, there is no reason to think that the breaking strength of carabiners is distributed along a gaussian distribution. We can generate distributions for which this number (0.3%) is a lot higher. Let's say our equipment is rated for 30kN, and some fraction "p" break at 29kN, while the rest (1-p) break at 31kN. The standard deviation is sqrt(p*29^2+(1-p)*31^2-(p*29+(1-p)*31)^2). Then 29kN is 3 sigma away from the when p=0.1, or 10%. So you can see that I've constructed an example where 10% of the samples break under the rating, even though the rating is set at three sigma below the average sample.

[@gerritroseboom8621]

While what you say is correct, I do have to disagree with no reason to think the distribution is gausian. In a whole lot of situations it is (by approximation). and I know that the breaking point with pulling from a rod is gausian. So my question is rather why would the distribution not be gausian? It can of course be the case, but in a whole lot of real world cases, distribution are gausian or logistic

[@HyperVectra]

yes

[@crazedvidmaker]

@@gerritroseboom8621 you make a good point. Many things are gaussian. It's worth thinking about why this is the case - the central limit theorem. If a random variable Y is made up of a sum of many random variables Xi, then the variable Y will be gaussian (or approximately gaussian if there aren't infinitely many infinitesimal Xi's). For example, the rod is probably gaussian because each point on the rod has its own independent breaking strength, and the breaking strength of the whole rod is the minimum of those. Climbing gear typically doesn't have such a symmetry which lends itself to a quick explanation of how the breaking strength might be averaged over many smaller variables. For example, there could be a particular bend on the carabiner which often has a particular small manufacturing defect - and the odds are say 10% that that defect happens and it lowers the breaking strength by 10%. Also, there may be one particular point on a piece of gear which usually breaks first, and then the breaking strength will be determined by a very small number of variables based on the few steps in manufacturing that small subsection of the gear. As a final comment, breaking strength cannot be gaussian because it can never be zero or negative. Of course, if the variation is small compared to the average, it could still be approximately gaussian (like a Poisson distribution for high mean)

[@ShurikB93]

I really think we should rethink MBS for webbing. Helium by raed and element by EQB, have almost the same MBS. And I know for a fact they will break differently in real life. Since slow pull is so easy to do, it is what we get. But we don't use really slow pull in webbing. We cyclic load and shock load, that is what needs to be tested. Really cant wait for the drop tower to be ready.

[@dragoscoco2173]

Shock loading achieves the same MBS or rather UltimateBS, just that for different materials with different elasticities, a shock load will attain different numbers for the same fall height and mass. The elasticity differs by material (obviously) and weave type (not so obvious), were the more parallel the fibers to the pulling direction the more stiffer (less elastic) a line or webbing becomes.

[@ShurikB93]

@@dragoscoco2173 obviously correct. And that is why MBS isn't a good figure to take into account. We need a combination of MBS, elongation, weight, and length of the webbing.

[@dragoscoco2173]

@@ShurikB93 The whole fall factor calculation is a nice simplification of the basic spring mass system in physics, to avoid needlessly complicated thoughts when high above the ground. Most ropes specify elongation at break or some other less engineered term and I am sure the dynamic/static ropes have a pretty well defined standardized elongation at break in their respective standards. As far as I know most of what you request is already available or it should be for a certified product.

[@ShurikB93]

@@dragoscoco2173 Not necessarily, Testing is really hard. Dynamic testing is even harder, MBS gives us "super good enough" certification, so most companies will do just that. My thinking is to think of highlining with more accurate thinking and not by MBS

[@dragoscoco2173]

@@ShurikB93 Static testing is super good enough for establishing MBS. There is nothing to be gained by testing one item dynamically, as in both situations the item will fail at the same MBS (or rather UBS). The dynamic testing is to asses forces that can be encountered in impact or tensile situations and learn to mitigate or avoid them.

[@theecanmole]

Wow this was like the PHD dissertation of breaking bolts and MBS. Amazing effort that you have put in!

[@robbob_the_climber]

Your subscriber count has increased dramatically since this video. Congratulations and I really appreciate all the knowledge you share!

[@niknik0815]

Banger video man! Great stuff on all the 'what would happen if I did this instead of that' elements of bolts, bolting, bending and breaking.

[@SuperEgosan]

We should buy this guy a teleprompter.

[@Hermanhusband]

Straight up. Transparent. Honest. Well deserved kudos. Each bolt broken is useful data. Thank you for the effort.

[@slackmitra9553]

1.) Ryan, i have massive respect for your work. You and Kyriakos are the reason I started experimenting with making my own gear as well as testing it (and testing gears others make to answer questions beyond MBS). This does not mean i do not question what your findings are, they definitely have their short comings and it's important for everyone to understand that too and take it from there. You are single handedly generating so much data/tests within a year that would take a couple of enthusiasts like me a life time! You are inspiring a generation of slack/climb scientists. 2.) Highline gear science is interesting (and hugely unexplored) because we borrowed most of it from climbing even though our basic scenarios such as peak loads and standing tensions are very different from climbing. That leaves a world of things for us to explore and re-define. I strongly feels MBS only describes a small portion of data that a consumer should know about when purchasing highlining equipment. I am sure the ISA will be developing a more refined system but until then its up to garage engineers like yourself to help shape what direction the ISA can also explore. Something as basic as "what is the basic MBS of a particular webbing in a weblock (RBS)" is still not standard and that surprises me. We have an opportunity to define a standard from scratch, and we should take that opportunity to communicate technical things in as less of a technical language as possible (without compromising on safety or communication). 3.) Other factors i think that should be taken into consideration while rating highline gear should be: + Webbing UV Resistance (how many hours of exposure to X units of UV radiation until you consider retiring your highline gear. I beleive ISA is already looking into this and I hope this is something that is implemented soon, since webbing being used in a country like India or Australia may have different implications or compromise if its being used somewhere in Europe). + Webbing Abrasion Resistance (BC is the only brand i have seen that is mentioning this rating for their webbing although i do not know how this is calculated) if my gear had higher abrasion resistance i know that itll last longer and i wouldn't mind spending extra money on it. For example slackhouse octopussy vs. slacktivity marathon. + Deformation Force (~WLL) how much force is need to deform this weblock? or shackle or hangar? If a product is being the used the way it is intended to, then MBS means nothing. The Deformation force/WLL is more important because it indicates the max load you should take it to. Before i learnt that gear made in metal bends/deforms before breaking, i assumed that MBS equates to the max force you can apply on a product. I believe this is a dangerous assumption, specially with gear not being used the way its intended too, think spacenets or rope jumps or the next crazy project that a genius highliner comes up with. 4.) MBS ratings are defined by testing brand new gear. What about MBS of gear which has been heavily used for 1 year in high UV exposure, with a little bit of abrasion and has been loaded to more than 50% of its MBS? Someone might assume the MBS remains the same? (i dont think thats a safe assumption and just shows how little we know about our gear.) There are other things that could be explored too, but i am still thinking over them myself. I started my day with this video, even though i will never get a chance to use the CMI hangar i was able to understand a lot of core concepts as well the fact that we assume so many things to be true because of our lack of understanding of technical jargon. Infact many people might think that MBS is done with a single test, or MBS might be the average/mean of 100 tests, or that any piece of gear will always break, minimum, at the MBS, where in fact neither of these assumptions are true and my opinion is that most of these assumptions come about because standards/manufacturers are not making it easier for consumers to understand the technical jargon. > I beleive this is something that that we higliners/ISA/HNTH can take as an opportunity and do a great job of a standard so that people can understand in as simple words and concepts as possible. I apologize for my long essay, maybe if i lived in LODI this could have been a conversation at a weekly slackline meet. Cheers Ryan, keep doing what you are doing, keep improving as a scientist and as a youtuber cause thats a deadly combo right there!! -Much love from India, Navin.

[@jima4656]

Thank you for doing these tests the way that you do & explaining your methods as well as you do. This is very useful information.

[@digdouglasdig]

Keep up the amazing work, I like to and tend to see the positive and potential in the situations I find myself in from day to day. This is one of your best episodes; solid Truth, as usual! Service with a Smile!

[@danbestwick5188]

Keep up the Great work you have not done anything wrong, and are very professional in how you present you page! Thank You I enjoy watching and following you Ryan

[@Jack000222]

I am NO scientist and absolutely LOVE your content. However, a word to the wise, if those bolts were galvanized, be careful of that one that broke off in the tree. I have heard many tales of the quickest way to kill a tree is to drive a galvanized nail into the base. Keep up the great work! Super Good Enough has made it into my everyday life and my wife hates it!

[@jsailer2558]

Was coming to the comments to see if anyone else was gonna speak for the trees. Glad to see some treehuggers already made it.

[@HowNOT2]

No digging it out now!

[@Richplaceholder]

All the lags bolts he used looked like they were zinc not galv.

[@Jack000222]

@@HowNOT2 Of course not! This was more intended to be informational. I am definitely not a tree hugger and am more than okay with this test. The tree will heal just fine and more than likely be okay. And if its not, its your tree on private property. Do as you please. :) Again, no hard feelings from me! I love your stuff! Dont hate me!

[@dragoscoco2173]

@@Richplaceholder Galvanizing in bolts is electro-chemical zinc plating unless otherwise specified.

[@zippythinginvention]

Great job, improving the MBS of your channel.

[@krazy1z]

Always enjoy your videos! "Breaking Gear Fear" is a great slogan. We talk to guys all the time about being able to trust your gear before you can be comfortable doing your job. Totally understand the prop of the paper lol. Keep doing you and hopefully certain companies with extremely high priced lawyers start working with you instead of looking for ways to try and shut you up.

[@2brianfritz]

I enjoyed the video. Thank you for the time and energy to make it happen!

[@waynegriswold8953]

thank you for all the hardwork put into this video.

[@Masonwmasters]

I would love to see you pull to “almost” breaking strength and then hold it there for a day…or week. And see if it eventually goes. You’re always simulating a short and strong pull, but not strong tension for a long period of time.

[@jradd77]

That's valid and would be very useful info

[@Petros98223]

the manufacturer should be ashamed of themselves for marketing a safety device with an unrealistic laboratory rating, unrelated to actual use. Their product is intended to be used in real conditions and is a life saving device. What they should be listing on their gear is the acceptable max working load. not their laboratory determined ultimate strength, this is just very foolish on their part since it could lead to a costly, and not unreasonable, law suit after one of their customers gets killed. shame on them.

[@JustinVodden]

Another great video! It's been 10 or so years since I've been involved with ropes course administration, but the idea of a lag bolt into a tree being used doesn't seem likely to pass a ACCT inspection

[@aSinisterKiid]

It's interesting those hangers keep tearing in that same spot in the corner. It seems like part of their design or manufacturing process results in a weaker point. This is only a guess from what I can see visually but - It appears like they manufacture the hangers from a flat piece of metal and then probably use a "metal brake" to put the bend into the hanger. And when they do that it's actually fatiguing the metal in those inside corners. And when you put a massive load on the hanger and it causes the bend to "unbend" it immediately results in a tear on that inner corner. It is something I would examine if I were the company that made them and I would probably try to come up with a new process to try and avoid that flaw.

[@HowNOT2]

That was Larry's thought as well.

[@aSinisterKiid]

​@@HowNOT2 you made a very valid observation with the other hangers as well about the more general slope in that area. The "flaw" with CMI design might be easily fixed by just not bending the hangers to that 90 degree angle in the first place. It would be interesting to see if maybe they only did a more gradual 45 degree bend or even less like a rounded 25 degree bend could solve that "tearing" in that 1 corner. It was really interesting to see the result when you used the horseshoe link and it actually was able to spread the load more evenly on both sides. Honestly if I was CMI, I would be really thankful for your testing and research because ultimately it could lead to an even better design.

[@richardlumley2581]

@@aSinisterKiid the cmi hanger (and most hangers but its more pronounced with the CMI ones) concentrate all the stress on that one point, it could be improved by making the corner rad of the hole larger or increasing the bend radius. Years ago I did model some hangers and play around with changing the shape to get the most strength from the least meterial, ended up at almost exactly the same shape as a petzl coeur hanger. By increasing the diameter of the pin you use to pull on the test you help spread some of the force to the upper leg of the loop, it's a cheat to get the highest numbers out of the part. I spent many years in destructive testing and most of the job was coming up with ways to conduct the test so you got better results. If you are being paid to test things, it's in your interest to get the highest readings you can get in a defendable consistent way!

[@aSinisterKiid]

@@richardlumley2581 Yeah I used to work for a company that did X-ray, Ultrasound, NDT and Destructive testing for military and government contracts. I have experience testing much larger stuff like bridge bolts/nuts, helicopter/submarine parts, Aircraft carrier Jet launch system bolts and even got to do some fuel line parts for the ISS. I got to see all kinds of interesting stuff and try to help improve on parts and redesign flaws. So I enjoy seeing him testing industry standard stuff

[@gotta-jibboo9139]

Awesome stuff Ryan! I don't wanna freak you out, but maybe think about a plan for if you ever got a lawsuit for pissing some company off? Hopefully that won't ever happen, but acknowledging the possibility is probably a good idea? Much respect! You and Bobby are doing amazing work for all of us.

[@piercer4882]

From what I can tell from the video, the big difference in the 2 different hangers you tested, is the shape of the hole that is cut out, prior to the bend. The hanger that consistently tore, always did so at the sharp corner of the "D" shape. Whereas the hanger that broke at a much higher value, had an oval shape cutout. Between the hole shape and the material differences (mild steel vs. SS), I'm not surprised there is a large difference..

[@treenetweaves]

Hahaha that's a good one. We've learned our lesson out here in the windy desert and only use sliding-x anchors for our big highlines. I've seen the side sag of these lines go above 50 meters at times! It's a crazy thing to see in person :O

[@d37tae]

quasi-static "Super super slow" 21:57 is usually the industry standard for testing. Serious companies will actually break a few parts at different speeds, then do a dynamic graph of strength vs speed. Not to mention temperature, or fatigue frequency, etc. That is why big super serious companies often dial in one material, learn it super well, dial in the process, and just spend the rest of the time in design. It takes forever to properly characterize a material. $$$$$

[@dragoscoco2173]

All materials break at their respective Ultimate tensile strength slow of fast, as long as your are not reaching the speed of sound in said material, as that is something else entirely.

[@dragoscoco2173]

@@nobodynoone2500 Please elaborate. I could detail my statement more too, but I've got no idea what you consider wrong.

[@thedoddfishtreemonkey.7760]

Your channel is valuable, any climber, slack liner or mountaineer, novice or old sweat should dial in. Why find out through trial and error (vertical sports don’t allow many mistakes) when you guys can provide the knowledge ?

[@jeremywicker8304]

I love the transparency!

[@johngill5175]

Solid man! Nice work! Way to be transparent!!!

[@redpakiu]

"How you pull it, and the speed in which you pull it, will give you vastly different results" Hear hear I say. (Someone had to do it) Thank you Ryan, nice ep, and really shows the beautiful work you guys have done.

[@mathiasbjrkedal8364]

Love your content and must say you're doing the work of gods with this shit. I'm from norway, and here we get 3-4 months a year with good slackline/highline weather. My question is if you would be interested in doing some tests on webbing or different parts of a setup in negative celsius? It would be interesting to see how the cold affects the gear and possibly how ice on the gear would affect it

[@markpercival476]

I love how impartial and practicable you are. It is really important to tell everyone that if the strongest piece of gear is weaker than advertised still exceeds most of the rest of the gear 'super good enough' doesn't even need to be double checked

[@TheRedWon]

Very thought-provoking video, thank you.

[@CHASSYification]

lovin the vids though, great content mate

[@LoneVanMan]

Great video Ryan. 👍

[@NVRLONF]

Another solid video Ryan!

[@Tyrim]

About the weather part: steel loses its impact strength quickly below a certain temperature(for certain standard non rated steels this can be as high as 20c!). It is important to always use steel that is rated for the temperature range of the application.

[@MrDschubba]

Especially important if it’s raining liquid nitrogen

[@Tyrim]

@@MrDschubba you would be surprised how brittle some steels can get even when reaching just 10 or 0 Celsius. Yeah you can't bend them by hand, but they will lose more than half of their impact strength in some cases. And impact strength is really important in this kind of application.

[@jonathans6037]

Hi Ryan, the 'weather' effects they refer to are most likely temperature and humidity and UV degradation. (you might have already thought of this). Just as you i am super excited about the drop/dynamic testing. However it is especially in these kind of tests that temperature goes to play a bigger role. Steel will get more brittle at lower temperatures BUT aluminum will get tougher and more ductile at lower temperatures which is very interesting. Humidity has an effect on Timber therefore timber strength/flexture testing is usually done in a controlled environment with specific humidity and temperature. Plastics are also effected by temperature not only in their brittleness but also creep of the material. Depending on how low the glass temperature of the material is. As you know plastics (nylon an such) also degrade with UV exposure which can also be considered a 'weather' effect. I highly recommend noting the temperature during the drop tower tests. To give you some more in depth info as a European civil engineer: mild steel is rated using EN 10025 as for example S235JR, the JR indicates the Charpy impact value required to prevent brittle fracture. JR: needs to resist 27J at 20 degrees celsius. J0 needs to do the same at 0 degrees C and J2 at -20 degrees C. I am not an expert on metals used for carbines or the like and i am not sure how much they would be effected by temperature. However maybe you could do some 'backyard' science to check if temperature plays a role in drop tests. You would off course need a repeatable/replicatable test which gives consistent results to test this. Keep up the good work!

[@FallLineJP]

HowNOT2: “Nothing is easy!” Hard is easy: “hard is easy!”

[@the50pointcalvinist9]

"weather" I would assume is a reference to cold and heat, try a test chilling a hanger to subzero and heating one to death valley temps of 100+. That would be interesting.

[@jradd77]

That would make for interesting testing

[@malteser0212]

I've got a question concerning your glued bolts: I know you use 2 component glues, but you always talk about ac or epoxy glue or in general plastics. I am a metalworker in germany, doing many industrial glue in bolts and we use a special kind of quickcement like Fischer Fis V. Have you done tests on such or similar glue types? If I got something wrong pleased feel free to correct me. Greetings from germany.

[@ghaznavid]

Was that script written by your lawyer? Delivery was very different to normal. Weird to read a script for a video.

[@philipp__3671]

I really think this was a followup video to the hanger video he mentiones. It may be a apology of some sorts while still giving us entertainment. Or he is just trying out new ways to do the show. But I agree. it was weired

[@allstarwoo4]

While it’s good they defined their use case. It’s really sketchy that they don’t want to release their testing methodology. If they’re confident in their product they shouldn’t fear independent testing.

[@YannCamusBlissClimbing]

OMG this is geek material! Great job on this Ryan!!! I can see how you had to work 40 hours on this episode. It shows...

[@jamesguest162]

when they say the strength is weather dependent, it most likely has to do with temperature since this will affect the ductility of the material and also the strength

[@avoirdupois1]

It's a good bet that very cold temperatures (-50C or lower) as well as salt and water exposure can affect the breaking strength of metal fasteners, and that's why the company mentions that.

[@papaspeleo]

The UIAA standards can be found on their website. From the drawings you know enough for the testing (not manufacturing)

[@calebdeming5515]

Very diplomatic. Cheers

[@Ataraxia_Atom]

How not to Mythbuster! Thanks Ryan great content

[@gimpdoctor8362]

Honestly if companies included a leaflet showing testing criteria and results for different use cases it would not only be more informative than MBS but would be solid marketting and probably save a lot of customer relations issues

[@colinboice]

Looks like the CMI hanger has significant room for design improvement, in the flat pattern they have sharp interior corners in the portion you’re attaching to which leads to a stress concentration at the corner which is where you consistently saw it break, since this is a stamped part they could easily have added an increased radius to improve breaking results. This is the major difference between the custom hanger you had made and their design

[@Aljonone1]

Have been in DMM Shop when they are testing gear & sound is super loud ! If load on a rope is getting close 10KN you are likely going to get whiplash in a fall?

[@7thrx]

Does the glue have temperature ratings and set times? What about moisture or oil guidelines (from tools and cutting lubrication)?

[@luke5897]

I bet the slow loading increases the heat and weakens the metal substantially. If it was loaded immediately, like it would be in a huge fall, it would probably hold more right?

[@soundman6645]

THIS is why in industrial lifting and rigging we deal in Safe Working Load or Working Load Limit with a mandated safety factor, dependent on the type of gear. AND we regulate, work and calculate in the stamped load rating only. AND the means of testing is specified in minute detail. In hard gear like shackles and hooks, the mandated safety factor is typically 4:1, but many manufacturers at least double that and proudly say so. AND in life dependent loads we typically double the safety factor, by using gear at half it's rating. It is worthwhile noting that very little if any "lifting gear" is folded or welded. ( trusses and lifting frames are exceptions) This Whole "minimum Breaking Strain" can get pretty dodgy, depending on the country and industry of origin. We have seen similar issues to what you have found with 4WD recovery points.

[@teamoutkastrcdragracingrev2933]

D/D ratio plays a large part, knots can reduce the load up to 75% depending on the knot. For fall protection, everything has a MBS of 5,000lb. I would bet it was pulled in a vertical pull, most everything i test at work, we go vertical

[@ridin1314]

The hanger should be bolted to a large piece of steel vertically & perpendicularly inside the snap machine then pulled on. That’s how they get the rating. Both legs of the loop see identical tension this way.

[@HowNOT2]

"That's how they get the rating" Source?

[@timrichmond6238]

When they referred to weather, is that because metal is more brittle in cold temps?

[@purple0burtle]

I assume that they refer to the weather having an effect on the tree/wood. If the weather is hot and dry for a long time the outer portion of the tree (newer growth) will be affected. If there has been very cold winter or a very wet season, the tree is slower or faster growing respectively. These factors have different effects on an anchor that has been set for a while.

[@satanaz]

@16:51 "Bend radius" are the words you're looking for to explain that

[@sc9160]

it's interesting, because CMI says on their website now that these hangers are not to be used for climbing or slacklining.

[@momoniji6439]

No way this guy made an apology for a company falsely advertising their life support equipment. 😂

[@adibpaulus]

Is there a company out there that could test climbing gears? We hired a subcontractor (mountaineers) to survey our sites but as due diligence, we want to ensure that all the gears are tested and certified. Since this is my first time in regards to the climbing gears, I'm not sure if it should or can be treated the same way as lifting gears/accessories?

[@AskTheKid]

I don't think you should have deleted it. Results are results and we watch you for your reaction to the results.

[@AskTheKid]

You could have cleared up your blunder in the video without removing data available

[@KamakaZex313]

Don't let the big wigs bully you because you gave a scientific and honest review of a product, it its not rated to what they are saying facts are facts and the people deserve to know what the safe limit is right!?

[@sparrowm249]

They're meant to be on allthread that goes all the way through the tree and is nutted on the other side, this will probably produce numbers above what you're seeing...the lags will pull out way before

[@HowNOT2]

Source? Product website says lag screw at the moment. cmigearusa.com/collections/rigging-hardware/products/bhanger?variant=640162233

[@robinj1052]

In my line of business, lifting, MBL (minimum breaking load) is the minimum load at which each product will fail. That means that not a single product will fail below MBL, as long as the product is used the way it is designed to, in good condition and conform the manual. The test procedures are laid down in standards from institutions like DNV, Lloyds or BV. The SWL (safe working load) is the maximum load allowed to be applied during use of the product and there is a factor of 4 to 5 between SWL and MBL. They should adopt this type of rating for climbing gear as well. One issue is that is is much more likely to get a dymamic peak load on climbing gear than it is on lifting gear, making it slightly more complicated to rate the equipment. Also the material in which the equipment is used, type of rock eg, makes it more difficult. But MBS should always be the minimum load at which a product fails, not some sort of median or average.

[@ralfrussel1950]

15:00 I think the biggest influence of the weather is the temperature. For textil materials humidity might also influence results. Would actually be intresting to test a wet rope or icy rope.

[@HowNOT2]

Testing wet and icy ropes is in the plans.

[@sendit2873]

if they got mad then it should have been up to par and broke them same as you you did the right thing

[@johnnycigar3240]

what do you think about the arbitrary nature of working load limits?

[@rmyklatun]

Best video so far.

[@TakeoElite]

Weather seems to reflect on temperature. Higher temperatures means more bending of metals. This of course can change results

[@danwang6361]

What is the rating for a compressing force to break a cerrified carabiner?

[@mabs503]

What I'm missing from all climbing gear is a "Maximum load" declaration derived from testing according to an ISO standard. We are talking about personal safety here, not machine safety. Minimum braking strength is just one input. When does the part disform? How many repetitions are ok before breakage? What safety margins does professional arborist, or scaffolding builders equipment legally have to fulfil? Standardised testing is the key here, and standardised ways to calculate a "maximum load" rating.

[@teddy_bearc_bolten3885]

I really wish someone would do an arborist addition of this stuff.

[@HowNOT2]

Its on the list!

[@wcakgilleran]

@@HowNOT2 Thats sweet! Can't wait!

[@bryantm6]

Screws in wood are usually stronger in tension than shear! Lots of highliners and climbers like me fail to understand that. I used to make the same mistake because I'm used to rock. Think about the soft wood surface especially bark. In shear you don't have the support on the surface like in rock and you get more leverage effect and start bending the shaft. On a wedge bolt you have one spot at the bottom of the hole exerting pressure but with threads you have shelves throughout the hole. In wood the fibers hold the threads really well in tension. In rock the stiffness of the material holds the shaft of a wedge anchor really well in shear. So it's not that the lag bolt you used was necessarily bad it's just that it's strength is in it's application in tension. You would have known that and probably commented differently if you were a carpenter as I had to learn that lesson from my carpenter friend.

[@kadmow]

lol, for Critical lifting and life safety gear - WLL is the one number which should be observed--- Fatigue is a thing. (Safety factor 3,4,5,?) 4WD recovery - non lifting, MBS may be a useful guide for purchase only. Critical link - weakest component limits the whole system..

[@michaelbrowder1759]

No trees were harmed in the making of this movie.

[@t4thfavor1212]

All those welds breaking have me reliving my structural welding classes...

[@navenridge]

With your custom hangers you countersunk the hole, reducing its thickness. Could that not have been the weak link to start the tearout of the hole?

[@HowNOT2]

Easily but still so strong enough it was difficult to figure out how to break.

[@philsponsel3824]

The Slogan "super good enought" is super good enought, not more to say!

[@benjefferson8609]

Breaking gear fear sounds like an amazing motto or slogan

[@dr.doppeldecker3832]

Have you ever thought about drilling holes in block of metal to test the bolts? This way you don't have to work with rock that will break way before the bolt.

[@stevedye3121]

Try using Spax brand lags. I have found them nearly indestructible. US /German made