What do you learn from destruction tests?

[l2lku2]

I would hate for my mountain bike to ever break while I am riding it hard. Can someone please point me to some bicycle destruction tests where someone breaks bicycles with hammers? MTBR does not seem to have them.

P.S. I don't think that I will every ride my bike that hard, but I like to imagine that I could our would.

 

[Planterz]

Ok then, let's not be scientific. Let's be use common sense. If a knife(say a battle mistress) can only be broken by being clamped in a vise and bent with a cheater bar, then it would probably not be a strain on common sense to assume that another battle mistress would be around as strong as that. It can be much weaker(unless it's defective) that it can stand prying apart a particle board from a frame since it only needs your brain to see that the second task is much less abusive than the first.

I still say you're still thinking in the wrong direction. Breaking a knife in a vice doesn't necessarily mean that prying apart particle board with it won't break it. Pinpointing what a knife can't handle can only be found while finding what it can handle. And people want to know what they can do with their knife before they know what they can't do.

 

[cziv]

This is maybe off topic from what you guys are discussing, but I happen to own some (5) of the knives that heve been tested and except for the CS kukri machete, they all break at some point. I liked watching the tests and seeing them earn 4 blades and higher and what "did them in" exactly. It gives me a certain amount of satisfation to know that if I use my "teted:" knives, I'm going to have very trustworthy and probably long lives of solid knife use from them. Just sayin....

Also Noss, for some reason will find a chip and keep working the same damn chip until he breaks the knife. I learn (I think) that if I find a chip or flaw and possibly stay off of that spot, my knife might make it even longer - for cutting wood or other normal knife chores besides slicing angle iron.

It's more interesting if yu own the knife being tested. IMO

I would hate for my mountain bike to ever break while I am riding it hard. Can someone please point me to some bicycle destruction tests where someone breaks bicycles with hammers? MTBR does not seem to have them.

P.S. I don't think that I will every ride my bike that hard, but I like to imagine that I could our would.

Send it to Knife tests dot com and maybe Noss will cut it up with a Battle Mistress!

 

[ISP 5353]

I learned never to let that guy borrow my knife!

 

[singularity35]

I still say you're still thinking in the wrong direction. Breaking a knife in a vice doesn't necessarily mean that prying apart particle board with it won't break it. Pinpointing what a knife can't handle can only be found while finding what it can handle. And people want to know what they can do with their knife before they know what they can't do.

Yes, you are correct in saying not necessarily but that is just nit picking. The more reasonable assumption which will probably be right 90 percent of the time, is that a knife of the same kind will be around as strong as the knife tested. And will therefore be able to handle less abuse than what the test knife went through. Now how do you decide what is "less abuse"? That's where your powers of observation and experience come in.

Do you really think that a person who makes the assumption than an ESEE-6 can pry open a car door because he saw a destruction test of one, is so far wrong?

It's like if I can bench press 150 pounds, then it's a reasonable assumption that I can bench press 100 pounds which is lesser, no?

 

[Dr Heelhook]

I like long period use tests better.

 

[singularity35]

I like long period use tests better.

I like knife tests.

I believe that if we keep an open mind, that there is potentially something to learn from each one.

 

[Planterz]

Yes, you are correct in saying not necessarily but that is just nit picking. The more reasonable assumption which will probably be right 90 percent of the time, is that a knife of the same kind will be around as strong as the knife tested. And will therefore be able to handle less abuse than what the test knife went through. Now how do you decide what is "less abuse"? That's where your powers of observation and experience come in.

My point is that you cannot know what constitutes "abuse" until you know the limits of what it can handle. Until then, knowing what it cannot handle is simply abuse, and then by definition, arbitrary and undefinable. Unless tested to the point of what said knife can handle, which is essentially the same as going the other direction (just more expensive), which noss4 has not done.

Do you really think that a person who makes the assumption than an ESEE-6 can pry open a car door because he saw a destruction test of one, is so far wrong?

It's like if I can bench press 150 pounds, then it's a reasonable assumption that I can bench press 100 pounds which is lesser, no?

Fallacious argument. Starting at an extreme assumes failure (especially if said test results in failure). Breaking a knife doing one thing but assuming it won't break doing another (which hasn't yet been tested), is more akin to not being able to bench press 600 pounds and therefor assuming you can bench press 500 lbs, when it hasn't been tested that you can bench press 500 lbs. Again, you're thinking in the wrong direction.

 

[singularity35]

My point is that you cannot know what constitutes "abuse" until you know the limits of what it can handle. Until then, knowing what it cannot handle is simply abuse, and then by definition, arbitrary and undefinable. Unless tested to the point of what said knife can handle, which is essentially the same as going the other direction (just more expensive), which noss4 has not done.

Fallacious argument. Starting at an extreme assumes failure (especially if said test results in failure). Breaking a knife doing one thing but assuming it won't break doing another (which hasn't yet been tested), is more akin to not being able to bench press 600 pounds and therefor assuming you can bench press 500 lbs, when it hasn't been tested that you can bench press 500 lbs. Again, you're thinking in the wrong direction.

We seem to be at different wave lengths here. You seem to want certainties and "guarantees" that's why you are not taking anything from the the "tests" . I am just talking about reasonable assumptions, and that's why I know that I can make educated guesses. Of course, it's not a certainty that a knife will survive what has not been tested but it's a reasonable assumption that it will survive lesser abuse than what destroyed a similar specimen. Of course you want to get to the extreme because whatever is not the extreme is by definition, lesser than the extreme.

We just seem to be talking circles here. You are not gonna convince me and I am not gonna convince you. When presented with a particular situation, you retreat to absolutes and refuse to accept that in the real world our decision and judgments are mostly based on reasonable assumptions since we never have complete data.

If we take your argument far enough and even if we have tested 1000 specimens of a particular knife in precisely the same way, the 1001st knife still has a possibility of not performing the same way as the previous 1000. But if we go real world, the reasonable assumption is that it will perform as 90 of the others have.

In the end we will never have certainties, only reasonable assumptions based on incomplete data.

 

[l2lku2]

Send it to Knife tests dot com and maybe Noss will cut it up with a Battle Mistress!

I am conflicted now because I am not sure whether cutting things with the Battle Mistresses will be valid tests of representative use because nobody seems to do it. But clearly beating things with a hammers is a well accepted test of representative use because somebody does it.

I am now worried about all the things we use that endure stress and impact, my skis, kids' skateboards etc. because I have not seen hammer destruction tests of those yet but I can't find those on the appropriate forums.

I will post the links when I find them.

Also, any recommendations for good backpacking hammers and hammer/knife piggyback sheaths? I have no experience with them yet. I would prefer survival or tactical type hammers. Also, any links to destruction tests where those hammers are destroyed with other hammers will be very useful.

I need to think more about saws. We use them to cut things, just like knives, but we don't baton with them so I don't know whether hammer destruction tests for those cutting instruments are representative. With axes, that do endure impact stress, would beating the head, or the handle or both with a hammer be considered representative testing?

This is complicated.

 

[Planterz]

We seem to be at different wave lengths here. You seem to want certainties and "guarantees" that's why you are not taking anything from the the "tests" . I am just talking about reasonable assumptions, and that's why I know that I can make educated guesses. Of course, it's not a certainty that a knife will survive what has not been tested but it's a reasonable assumption that it will survive lesser abuse than what destroyed a similar specimen. Of course you want to get to the extreme because whatever is not the extreme is by definition, lesser than the extreme.

My point is that one cannot assume what "constitutes assumption" on what a knife can take unless one knows what it can take, or is intended to take. I can't fault you for taking an educated guess, but I can fault you for what you're taking that educated guess from. If that guess comes from a single data point under unrepeatable or unrepeated circumstances, then I take issue.

Radon detectors trigger when the levels become dangerous, not when they prove fatal. Just like knives, I don't want to know when they're beyond safe useage, I want to know what that limit is.

 

[singularity35]

My point is that one cannot assume what "constitutes assumption" on what a knife can take unless one knows what it can take, or is intended to take. I can't fault you for taking an educated guess, but I can fault you for what you're taking that educated guess from. If that guess comes from a single data point under unrepeatable or unrepeated circumstances, then I take issue.

Radon detectors trigger when the levels become dangerous, not when they prove fatal. Just like knives, I don't want to know when they're beyond safe useage, I want to know what that limit is.

I never seen a more obfuscating statement than that. Destruction "tests" don't destroy a knife directly. They usually start out with simple tasks and escalate the abuse until the knife breaks to indicate the point where the knife will break. To read your statement, it's like a destruction tester just clamps the knife directly in a vise and breaks it with a cheater bar. That's where all your arguments about not knowing what is "lesser abuse" is invalidated.

How do you know in the first place which levels are dangerous if you don't know which levels are fatal? If you don't first determine at what point the radiation is fatal, you can't make a determination of danger.

 

[timberweasel]

I prefer the kind of knife testing as demonstrated by Adam from Equip2Endure (ex. http://www.youtube.com/watch?v=ZQkHbpnnb2k) where the knives are being used for actual/realistic tasks. This method could also be deemed 'unscientific' as the tests are conducted in the field rather than the laboratory--no use of measuring equipment that gauge/control mechanical factors, the material (wood) being cut and chopped is likely inconsistent with each trial sample, and only one knife specimen is available for testing. Regardless, I find it a much more reliable and useful data-point than watching someone try to baton a knife through a length of steel rebar with a ball-peen hammer--I just don't see myself ever needing a knife to survive the things Noss does in his videos and I find it difficult to relate. YMMV, I reckon...

 

[Maddogg774]

What some of you "scientific" minded people seem to miss is that Noss, for example put multiple knives, from different manufacturers thru the same tests. The manufactures claim toughness and consistant quality, so if you take them at their "word" if one fails from example A, all will fail from example A (Chris Reeve GB) of the same exact knife. If example B(Scrapyard scrapper 6)far outperforms example A, it will every time...if you believe the claims of the manufacturer.

 

[singularity35]

deleted.

 

[unit]

It's the "inconsistent and unrepeatable" arguments that the "scientific" guys come up with, that I find issue with.

Chuck, let me give you an example of what I believe others are discussing.

Put a knife in a vice and put a pipe on it and apply exactly 500 pounds of lateral force at a point 5 feet from the vice clamp and the knife does NOT break. Now re clamp the knife in the vice apply 501 pounds of force at 5 feet from the vice and the knife breaks. What does that show us?

Actually very little because we did not standardize where the vice was clamping the knife! See what I mean?

Stab and pry tests are FAR worse in that the blade geometry may dictate how deep the knife penetrates before the prying occurs.

These things are entertaining, but the utility of them is debatable. If you find them useful, that is your call...I would have a hard time putting much stock in the ranking of one model vs. another based on these "demonstrations" (which is what I call them, because they are only a "test" in a similar manner of a room full of screaming kids is a "test" of a substitute teacher)

Respect to all! Just my thoughts.

 

[allyourblood]

I watched a couple of videos and found, disappointingly, the answer to my own question: only one specimen is being "tested". What a complete and utter waste of time.

And knives.

 

[singularity35]

Chuck, let me give you an example of what I believe others are discussing.

Put a knife in a vice and put a pipe on it and apply exactly 500 pounds of lateral force at a point 5 feet from the vice clamp and the knife does NOT break. Now re clamp the knife in the vice apply 501 pounds of force at 5 feet from the vice and the knife breaks. What does that show us?

Actually very little because we did not standardize where the vice was clamping the knife! See what I mean?

Stab and pry tests are FAR worse in that the blade geometry may dictate how deep the knife penetrates before the prying occurs.

These things are entertaining, but the utility of them is debatable. If you find them useful, that is your call...I would have a hard time putting much stock in the ranking of one model vs. another based on these "demonstrations" (which is what I call them, because they are only a "test" in a similar manner of a room full of screaming kids is a "test" of a substitute teacher)

Respect to all! Just my thoughts.

Yes, but what I'm trying to say is that whether the knife broke with 500 or 501 pound of force, it's a reasonable assumption that it will survive 300 or even 400 pounds of force. It still shows us that the knife is effing tough and that any reasonable use will not destroy it. If 500 pounds was applied 5 feet from the clamp, for sure, you're not going to be applying that amount of force in a "real world" use. Which means that the knife won't break in your real world use. What I'm saying is simple, if it takes a lot to break a knife, then you'll know it's a tough knife. And it's a reasonable assumption to make that 90 percent of that kind of knife will be around as tough as the one tested. And it will take as much abuse to break it.

 

[upnorth]

I prefer the kind of knife testing as demonstrated by Adam from Equip2Endure (ex. http://www.youtube.com/watch?v=ZQkHbpnnb2k) where the knives are being used for actual/realistic tasks. This method could also be deemed 'unscientific' as the tests are conducted in the field rather than the laboratory--no use of measuring equipment that gauge/control mechanical factors, the material (wood) being cut and chopped is likely inconsistent with each trial sample, and only one knife specimen is available for testing. Regardless, I find it a much more reliable and useful data-point than watching someone try to baton a knife through a length of steel rebar with a ball-peen hammer--I just don't see myself ever needing a knife to survive the things Noss does in his videos and I find it difficult to relate. YMMV, I reckon...

With all due respect, I see Adam doing nothing more than what many of us have done with our own knives before. Noss does all that and far, far more. I want to know that if I'm in the boonies and break a leg that I can trust my knife to hard use. No one is forced to watch them.

 

[timberweasel]

Put a knife in a vice and put a pipe on it and apply exactly 500 pounds of lateral force at a point 5 feet from the vice clamp and the knife does NOT break. Now re clamp the knife in the vice apply 501 pounds of force at 5 feet from the vice and the knife breaks. What does that show us?

This raises another interesting facet to the discussion, Unit. Has the initial stress somehow diminished the blade's capacity to handle the extra weight? Consider climbing gear... it is recommended that spikes, carabiners, straps, buckles, ect. be replaced after 'x' amount of use regardless of their initial rating. There is a finite life-cycle expected for these tools and you wouldn't really want to risk pushing the limits when you're going to be dangling from a rope 1500ft above the deck on a mountain somewhere...