Why don't we have lightweight steel carabiners?

Ryan Hamilton wrote:

Clearly we all know that it's not going to slice the rope, unless taken to the extreme, but the point is that a thin diameter steel carabiner is going to cause a lot more damage to a rope on repeated falls than a wider aluminum carabiner. Lest we forget, accidents have been caused from aluminum carabiners that have been so warn down that the surface was thin (and sharp?) and cut the rope when someone fell on it. 

BD has done some testing on this the edge is definitely very sharp, the overall radius of the biner really can be quite small if anybody here has the 19G carabiners you will get what i mean. My original thought of a steel carabiner would actually resemble more like a weird form of wire gate but as Tut helpfully pointed out i don't know much about biner design it's almost as if the title of the thread  didn't imply this.

that guy named seb wrote:

BD has done some testing on this the edge is definitely very sharp, the overall radius of the biner really can be quite small if anybody here has the 19G carabiners you will get what i mean. My original thought of a steel carabiner would actually resemble more like a weird form of wire gate but as Tut helpfully pointed out i don't know much about biner design it's almost as if the title of the thread  didn't imply this.

Look dude, I don't like being salty. I really don't. But when you imply with your flippant *cough* that others are not seeing something you alone are, but in fact you are failing to grasp their point its kinda hard not to be salty.

Every time someone has intelligently pointed out why lightweight steel biners are a terrible idea for a myriad of reasons, you never seem to think about it and instead dispute their points.

Take this as an opportunity to learn about Hubris and how it can be a barrier to learning.

King Tut wrote:

Look dude, I don't like being salty. I really don't. But when you imply with your flippant *cough* that others are not seeing something you alone are, but in fact you are failing to grasp their point its kinda hard not to be salty.

Every time someone has intelligently pointed out why lightweight steel biners are a terrible idea for a myriad of reasons, you never seem to think about it and instead dispute their points.

Take this as an opportunity to learn about Hubris and how it can be a barrier to learning.

My point with you simply that a small radius wont cut through a rope that's it, of course it's not nice on the rope but it's not cutting through it.

As far as others go, I clearly stated earlier that this whole thread was simply due to poor google fu on my end and not getting my numbers straight.

that guy named seb wrote:

My point with you simply that a small radius wont cut through a rope that's it, of course it's not nice on the rope but it's not cutting through it.

Really, and have you seen the standard that the UIAA sets for testing ropes? It also has a requirement for the radius of the edge the rope runs over in their severe test falls. 

Do you know where the rope commonly fails in such testing? Over that edge.

That wire on the gate would destroy a rope in a short order on a UIAA test rig. It would slice through the rope like butter.

Watch this video and tell me what you see:

https://www.youtube.com/watch?v=_J_Eu6IO6DE

that guy named seb wrote:

As far as I'm aware there are steels with better strength to weight ratios than 7000 series aluminium so why don't we use them? If we can make a 19g fully rated biner surely a steel biner could be even lighter.

climbing friend,

because the jesus he hates you

King Tut wrote:

Really, and have you seen the standard that the UIAA sets for testing ropes? It also has a requirement for the radius of the edge the rope runs over in their severe test falls. 

Do you know where the rope commonly fails in such testing? Over that edge.

That wire on the gate would destroy a rope in a short order on a UIAA test rig. It would slice through the rope like butter.

Watch this video and tell me what you see:

https://www.youtube.com/watch?v=_J_Eu6IO6DE

http://theuiaa.org/documents/safety-standards/UIAA_101_7_ropes_may_2016.pdf

You're vid is years out of date and they don't do that test anymore but i'm also pretty sure that's a sharp edge, no way would there is simply no way something like the edelrid 19g would make it to market if all that was needed to cut the rope hell pretty much any micro biner has a tiny cross section the rope bearing radius smaller than that in the video linked above.

that guy named seb wrote:

http://theuiaa.org/documents/safety-standards/UIAA_101_7_ropes_may_2016.pdf

You're vid is years out of date and they don't do that test anymore but i'm also pretty sure that's a sharp edge, no way would there is simply no way something like the edelrid 19g would make it to market if all that was needed to cut the rope hell pretty much any micro biner has a tiny cross section the rope bearing radius smaller than that in the video linked above.

Remember what I said before about Hubris and how you never take the time to understand what someone more knowledgeable is showing you and instead you dispute it?

And there you have it.

You two be nice and stop bickering. 

Seb, yes a smaller radius of micro biners (as opposed to full size biners) obviously won't cut the rope unless it's subjected to multiple high impact falls. On the other hand, they aren't nearly as nice on the rope as something like a metolius element. But each time you shave a fraction of a milimeter off the biner radius, you're getting a little bit closer to the a very small radius you might find on something like a butter knife.

The smaller the radius, the riskier it gets. Manufacturers typically want minimize their risk exposure, so making a biner that could potentially cut a skinny rope in a high FF fall isn't exactly a great business model. 

King Tut wrote:

Remember what I said before about Hubris and how you never take the time to understand what someone more knowledgeable is showing you and instead you dispute it?

And there you have it.

So let me get this straight, I have excessive self pride because i backed up my argument with current up to date testing methods and real world examples of where a small radius is fine on the rope, I got this straight Tut? Tut you are the person saying you are more knowledgeable and then providing nothing to back it up i'm not the one claiming i'm an engineer or actually know about carabiner design that's why I ask questions on MP. If someone says something that doesn't sound right I will google it and if it's wrong i will call them out and that's what i'm doing to you, I present my evidence to you and wait for a response, for you to either concede or refute what i have said, this is how discussions work and if you can't manage a relevant response don't respond.

that guy named seb wrote:

So let me get this straight, I have excessive self pride because i backed up my argument with current up to date testing methods and real world examples of where a small radius is fine on the rope, I got this straight Tut? Tut you are the person saying you are more knowledgeable and then providing nothing to back it up i'm not the one claiming i'm an engineer or actually know about carabiner design that's why I ask questions on MP. If someone says something that doesn't sound right I will google it and if it's wrong i will call them out and that's what i'm doing to you, I present my evidence to you and wait for a response, for you to either concede or refute what i have said, this is how discussions work and if you can't manage a relevant response don't respond.

You don't get it bro.

I showed you a video of an rounded edge (clearly visible) with a vastly greater radius than any wire used in carabiners and it was shredding ropes in UIAA falls. Whether or not that is the current UIAA testing protocol or how old the video has nothing to do with anything. That edge in the testing apparatus was specifically intended to mimic the bend on the rope running surface of a standard carabiner.

Because it didn't show what you wanted to see you totally disregarded the entire take home message: The smaller the radius the edge the rope is running over in a fall will result in faster cutting of the rope and that edge (ie the carabiner) is **precisely** where the rope always fails in severe falls. That is why most modern carabiners are particularly fat there first, then durability over time second and precisely why thin stock is never, ever used.

You didn't back up anything. The entire point went **whoosh** over your head because you didn't want to see it instead of the education offered.

My credentials?

It was my job to know. Take it or leave it.

that guy named seb wrote:

If aluminium has a better strength to weight ratio than any common steel alloy then why the hell are wire gates lighter but still as strong? 

An aluminum solid gate is heavier than a wiregate because it has more components in it. A wiregate holds tension by bending the wire and mounting it to the body disproportionately so there is spring tension applied on the gate at all times. A solid gate is hollow and contains a steel spring, a steel plate below the spring, two steel rivets and then the aluminum gate itself. Thus, the answer to your question as to why the aluminum gate is heavier is because you're not just comparing two different alloys, you're comparing two different technologies. A solid gate consists of at least five individual components, some of which are steel, whereas a wiregate is basically just one part. If manufacturers made wiregates with aluminum stock, the carabiners might weigh slightly less than biners with stainless steel gates, but aluminum would not be an appropriate choice for a wiregate as the properties dont match the demand for the part. Wiregates need to be strong and bend easily without suffering from fatigue and aluminum doesent do as well in those categories, thus the wiregate is made from stainless steel.

I think Hank Reardon's steel mill has been working on this, but the Government has effectively shut his operation down. 

King Tut wrote:

Look dude, I don't like being salty. I really don't. But when you imply with your flippant *cough* that others are not seeing something you alone are, but in fact you are failing to grasp their point its kinda hard not to be salty.

Every time someone has intelligently pointed out why lightweight steel biners are a terrible idea for a myriad of reasons, you never seem to think about it and instead dispute their points.

Take this as an opportunity to learn about Hubris and how it can be a barrier to learning.

+1

King Tut wrote:

Because the steel can be made very thin for the gate, but can't be for the biner body or they will cut ropes. There is a certain cross section the rope bearing surfaces must have.

That is not the reason.

A big part of the reason is that a larger section of material as aluminum allows, enables a stronger piece.  If something is TWICE as thick it isn't twice as strong.  It would normally be significantly more than twice as strong due to the bending stresses etc.

A wire gate is different.  It is under tension only.  In tension high strength stainless steels can run pretty much on par with run of the mill aluminum on strength to weight.

It's all engineering.  Be assure that somebody has put a HELL of a lot of thought into it.

The reason that carabiners aren't steel isn't just because the rope bearing surface would be too small, it's also because the structure is loaded both in bending and in tension. That is every part of the carabiner except for the gate. This is what patto's post is getting at. 

From wikipedia, the formula for bending stress is this. Having a larger cross sectional area and even further and I beam cross section increases the I at the bottom of the equation, reducing the maximum bending stress. A steel carabiner of the same weight would have to have a much smaller cross sectional area since the material is denser.

I suppose you could make a carabiner using a very thin steel frame, encased in plastic to provide the needed shape and handling, and finally put steel wear plates at the rope bearing surfaces. If you use clear polycarbonate as the plastic, it would be pretty tough and allow you to see the steel frame inside (though polycarbonate is fairly heavy).

Such a design would be far more complicated, expensive, and I think there are more opportunities for failure, and I doubt it could be much lighter than aluminum carabiners, if lighter at all. I don't think this would be practical at all. But purely as a matter of speculation, I think it could be done.

To be clear I think aluminum carabiners are fine and already fantastically lightweight, I think this would be a solution in search of a problem..

This discussion is not the same without bearbreeder.

patto wrote:

That is not the reason.

A big part of the reason is that a larger section of material as aluminum allows, enables a stronger piece.  If something is TWICE as thick it isn't twice as strong.  It would normally be significantly more than twice as strong due to the bending stresses etc.

A wire gate is different.  It is under tension only.  In tension high strength stainless steels can run pretty much on par with run of the mill aluminum on strength to weight.

It's all engineering.  Be assure that somebody has put a HELL of a lot of thought into it.

100% agree and should have listed the rope running surface as just one of the reasons why steel wire can't be used. Without question there are many, many reasons why Aluminum is ideal and as well (as currently) the forging processes that are used take advantage of all of them in a very cost efficient manner, something that cannot be done with steel.

A carabiner made of light wire would bend like the proverbial paper clip AND slice through ropes though it may test to a high strength on one axis.

At the end of the day it is all price to performance (and the ease of working Aluminum into the shapes we desire is very inexpensive to produce).

Forged Aluminum (into "I Beam" like shapes) is currently the complete package of ideal properties allowing economical production with all of the features we desire in some measure, including even anodizing of colors for our convenience.

ok just to watch the chaos....carbon graphite biners?

Mark LaPierre wrote:

ok just to watch the chaos....carbon graphite biners?

The main problem with carbon fiber is that it is very strong in tension, but weak in compression.  The main loading on a carabiner is actually in bending which puts one side of the biner in tension and the other in compression so it would take really strange geometries to get the requisite strength.  Also, carbon fiber has terrible impact resistance which means that the microfracture myth would no longer be a myth with a carbon carabiner.  Wear is also an issue, but that could be eliminated with something like a steel insert like the edelrid bulletproof.