Totally Impressed!

Cliff,
I agree that it is unfortunate that you can't trust everyone. I don't understand why something that is used to advertise a product can void a products warranty either. If you sell me a product and a video showing your product doing certain things, then it becomes part of your advertising. If you later void my warranty based on me performing the same tasks, it should be going against the "Truth in Advertising" laws.
Perhaps the manufacturer should include a warranteed statement of safe operating ranges (a reasonable one), rather than the limits. THus if a product could be bend 60 degrees before braking, instead of claiming that, they could state a safe range of say 40 degrees. This would let me as a user gauge the use of said product for the task I'm about to undertake and perhaps take a different one. The benefit for the manufacturer is that if I return said product broken and claim it happened while operating within their given range, they know I abused it since there was a 20 degree margin. So I must have really bend it 60 or more degrees.


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The impossible I can do right away, miracles take a little longer.
 
Cliff is a scientist. He gathers information, compiles it, and learns from it. He conducts tests, and experiments, and comes to conclusions based on thes experiments. The more tests that Cliff does, the better he gets at controlling variables. Variables, will always affect the outcome of tests, so they must be controlled, or accounted for. It is the same when I test my blades, or a factory tests there blades. There are alway variable. They know (factories, knifemakers, and Cliff Stamp) how the particular product will perform doing specific tests with the variables being the same as when they tested them. What they don't know (factories, knifemakers, and Cliff Stamp) is what variable will exist when and where you test the knife you get from them. Another point is that these tests (that factories, knifemakers, adn Cliff Stamp) do, permanetly alters the knives. Putting them in a position to fail under lesser circumstances later. In other words, if you match there test exactly including all variables your knife should pass, but will almost definitely fail later under lesser circumstances because of the stress added to the knife in your origanal test. That is why they don't want you to do what they show. If you do, eventually your knife (more likely than not) will fail, after having so severly stressed it from the test. It is for this reason, that I do not torture test a knife, then sell it. If I torture test a knife, I test it to complete failure, sometimes breaking the blade up to 7 times.

I hope that makes things clearer,

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Lynn Griffith-Knifemaker

griffithknives.com
GriffithKN@aol.com
Available Knives
 
bentpos.jpg

Here are 4 imported 420j2 steel knives that I just locked in a vise and bent. They all ben to beyond 90 degrees before breaking, except the damascus peice that broke at about 20 degrees in about 6 places (delaminated). All except the damascus lockback could be straitened back to almost true, with litte visible damage to the steel. The knive were then bent again to beyond 90 degrees untill they finally produced visible cracks. Any of these knives could take a razor like edge, and would be easy to resharpen. All would take a lot of abuse, and could be easily restore. All could be bought brand new for less than $20. All except the Damascus one for less than $10, and 2 for less than $2.



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Lynn Griffith-Knifemaker

griffithknives.com
GriffithKN@aol.com
Available Knives
 
Arizona, stating safe high use limits would be very welcomed indeed. I don't see a problem with marketting the breaking points either, but I do see that giving them without the safe operating range is problematic as it could lead to incorrect assumptions. For example if it is claimed by XXX that thier knife will break at 60 degrees, that does not imply that less than 60 degrees is safe. You could pass the plastic deformation barrier long before that and thus damage the knife.

Lynn , it is very true that using a knife in almost any manner will stress the steel. Take even the most basic use, chopping with a bowie. If you do this long enough with enough force and don't sharpen the blade you will eventually weaken the edge enough so that the cracks will cause a visible fracture and you could see chipping in the blade. However it is important to note that there are limits on all of this. For example I am pretty sure that if I had any decent bowie I would be able to get it to chip just by chopping wood if I worked long and hard enough, but I don't think I could grossly distort the blade by doing so as it would take far, far too long.

It is because of things like this you should be fairly descriptive of what you are doing and the stresses it places on the blade. For example I am writing up some work done on a 420V fillet blade now. The blade is ductile enough so that I can bend it and it will deform and not snap. I have described this and made sure to note that distorting a steel past the plastic limit (where it will not return to true) does stress the steel. Even if you can straighten it out the steel is much weaker. If you repeat the bend you will eventually fracture the steel and it does not take very long (on the order of say ten bends).

The issue is not simple, for example if you don't deform the steel but just let it flex and then return to true the amount of stress you have created is minimal (especially if the blade is selectively tempered so as to enhance the ductility in the high strain areas). While the blade will eventually break from fatigue, fatigue cycles in metals are very high (a low fatigue limit would be 10 000 cycles). It is because of things like this that when you are describing the results of a stress, you should note any significant strains that might have resulted even if they are not visible.

Lynn, thanks for the pics and the bending data. I have noted similar with the softer imported blades (mainly 420J2) they are very tough and ductile, low strength though.

-Cliff


[This message has been edited by Cliff Stamp (edited 23 December 1999).]
 
I have the tendency to agree with everyone. I remember the "good ole days" before the onset of the "super steels" when the deer camp was the testing ground for knives.

I also agree that major testing to the failure or destruction point has a place in the knife industry. This forum provides a whole lot of good information.

I feel that the negative aspect of today's range of testing methods is that several very good knife makers lose business because they make an excellant hunting or utility knife, but the knife won't bend without breaking or remain sharp after chopping down a forest.

The knife industry has room for everyone and not all users need the indestructible blade. I have knives I won't pry with and some I will. My point is that one should know his knife and the limits. All reasonable testing should continue and what constitutes abuse varies. I also agree that if a makers makes a public claim, that maker should be prepared for someone to call their hand. I respect the knifemaker that states his knife will break.

This is a good thread.
smile.gif
 
MTF3 :

I have knives I won't pry with and some I will.
Click to expand...

I have some blades that are that fragile that if I was to impact them off of a staple (to refer to a recent discussion), it could knock a chip out of the edge half the width of the bevel. I have blades that weak that I could very easily deform/break them just by holding the blade in my hands and twisting. *However* they have the level of strength and toughness for the level of work they were designed to do.

I respect the knifemaker that states his knife will break.
Click to expand...

I don't agree fully with some of what Lynn is saying, especially concerning some of the issues raised in a <a href="http://www.griffithknives.com/board/?topic=topic1&msg=140">recent thread on his forum</a>. However I do respect him for plainly and openly discussing the issue.

-Cliff
 
Well if we all agreed, then this forum would be boring. I am glad we can learn from the experiences from both maker and tester. Details from the maker and results from the tester becomes much desired information.

Two basic questions I would consider: 1. Would the tester buy from the knifemaker? And 2. Would the knifemaker object to the methods of the tester or would he consider the results as useful information?

The majority of users are now able to sit on the sidelines with an open mind and soak up knowledge from forum discussion. I am glad the knife impressed the user. I personally would not ask for warrenty repair from a maker after clamping a knife in a vise and stressing it, unless of course the maker claimed that the knife was designed for that purpose. I take testing data and knifemaker response in consideration when I make a purchase.

Keep up the good work, I will be on the sideline.
 
OK... Should I assume there are no other knives that have truly impressed anyone with their strength because my question remains unanswered? Does MicroTech own the rights to hard use knives? Doesn't anyone have a story to tell?

Les,
Your comment about the piton leads me to believe you truly do not understand my point:

"Regarding the climber, perhaps next time he should carry one extra piton."

And suppose he needed one more after that? I think an emergency would mean that you were not prepared for an event. If you are prepared it really isn't that much of a threat is it???

The whole idea is that if a true emergency(Les, this is a situation which you are UNprepared for and have to make do with whatever is at hand.) arises wouldn't you rather have a knife that has been tested and known to withstand a certain amount of abuse??? Or would you prefer to take a risk and wager on a tool that may give way because you spent your money on a poor choice. One you made unknowingly because you had no data for comparison.

Lyn,
Those knives you pictured certainly could NOT be depended on as a foothold if they bend so easily!!! I definately would not want to have to pry open a door if I got locked out with one of those! I am surprised that the blades bent before the pivots failed though. I always believed that the pivot will be the first point of failure on any folder, but even those cheapies failed at the blades before the pivots. This seems contrary to popular wisdom.

I can think of many knives costing about what that SOCOM does that would definately not take the abuse that I saw one take, and there is no question that it is abuse, even though they are considered hard use knives. What if their users had wanted the toughest knives for the price and not gotten it? That would be the point of these types of tests in my opinion. These test and stories will help all of us make better informed decisions.

I understand that not everyone wants the "toughest" knife, but I happen to like the tactical type knives, and I like to think that when I am carrying one that I can depend on it if an emergency arises. So lets have those stories please!



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Al
 
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