Blade Performance Testing

A simple question: If a knife cuts well, is designed to do what is is supposed to do what more can you ask?
 
Allan Molstad said:
One type of cutting test Im not sure actually tests the cutting edge is chopping some sections of firewood.

There are many video clips on YouTube I have been watching as of late , where the knife maker is able to shave hair, then pound it in some firewood. The blade splits the fire wood, and then we see that the edge still shaves hair.

But is this chopping of firewood really testing the cutting edge?
Im not too sure it is because it would seem to me that the wood can be also getting split by the pure shape of the sides of the knife.
It might be true that chopping firewood does not cause that much harm to the cutting edge on a convex grind knife blade.
But I would agree that chopping firewood is a good way to test the spine of a blade, to see how it works and how it stands up to this type of stress.
The handle can also be well tested by cutting firewood because once the blade gets stuck you may have to twist and bang on the handle to get the blade free."

I guess the real question is what wood are you chopping. Normal chopping will test the knife/steels toughness more than anything if I understand it right. But chopping hard wood would test the strength of the edge/steel as well wouldnt it? The real problem would be finding some teak you would be willing to chop on in the first place. Im tameshigiri we would cut both fresh and dry bamboo. I always got the imression the hardness of it was testing both wether the edge was deforming and the differential HT.
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Perhaps, and I dont really know what type of wood would make the best test with.

However I think that if you want to do a chopping of wood test, that you might think about a wood that you will need to chop in real life.
Like a local wood that you find in your area.
This would allow you to perform the same type of test later with a different blade and then be able to compare the results.

A test of an edge and it's ability to cut and stay sharp is more usefull if you do the test using things that you can cut again in the future.
A pointless cutting test would be where you cut something once that you will never be able to cut the same thing again to campare with later.

EXAMPLE:...Lets say a guy does a cutting test where he cuts a 1-inch high stack of $100 bills...

Yes, that would be an "interesting" test to see on YouTube, but it's a pointless test for someone to try to use to compare their own knifes to. Because noone in their right mind will try to cut $10,000 in half to check their knife.

I also dont know about the test where I might take a knife to work with me to see how it is in real life situations.
Again, such a test is interesting, and I might learn many things from it, But the problem is that every day at my work is totally different.
I cut different things all the time.
Therefore the results of a real life situation test cant be repeated the same way in the future on the next knife.

Cutting wood?
Again Im not sure that harms the cutting edge that much.
It could, I dont know for sure, but I do know when I split wood with a log splitter that there is a little gap that forms infront of the wedge many times. This might mean that when a knife splits wood that there could also be that same little gap infront of the blade as the sides of the knife split apart the wood a head of the edge.
 
Even if I could find teak I dont think I would cut any up for knife testing. :p But if I understand my properties of steel right the harder the wood the more it would test edge strength. Wood is softer than metal so I dont think should dammage it much as long as the impact resistance of the steel is up to the job (assuming correct RC for a chopper that is). Still knives get dull for different reasons. If you were chopping a hard wood (probably doesnt happen much) you would get some dulling due to edge deformation. I guess it deppends on what the choppers for. If you live around dense wood and thats what you are chopping up in camp edge strength would need to be good. If the chopper is for cutting competitions then I think 2x4's are as rough as it gets and toughness would be the most important factor. IMO good choppers shouldnt be to thick in profile so they shouldnt be splitting the wood yto the extent that the edge isnt getting full contact but after going so far into the wood the wedge profile might start to split the wood before teh edge hits it. I guess I would think wood chopping could tell you things about your knives preformance as long as you were shure of what you were trying to test and what to look for. Then again if your not making a chopper at all I would have to agree that its probably more fun than telling.
 
Be careful with statements like that Alan and Big Jim, you are dangerously close to one of the secrets of blade demonstrations, and also a significant aspect of geometry.
 
I did not mean to kill your thread, intended to encourage it. Go ahead and explore the thoughts you were sharing and see where it goes!
 
So... it turns out that some methods of demonstrating blade qualities may not be actually demonstrating what they appear to be or at least may not be so valuable as tests (but great for impressing potential buyers).

As noted above to attain the maximum benefit testing needs to be repeatable with other knives by other makers and in different locations.
 
mrnewberry said:
As noted above to attain the maximum benefit testing needs to be repeatable with other knives by other makers and in different locations.
Click to expand...
Very true.
When I watch on YouTube where a guy cuts a 1/2 inch section of rope about 100 times before it gets too dull, this gives me a chance to judge my own knife by too.

I can forge that same type of blade from that same type of steel.
I can get that same type of rope and I can see how many cuts I can get before it's dull.
And I can do this the same way years from now.

Taking a knife into the kitchen or the shop, or to work or deer hunting to test it in real-life situations is important too, but such results cant be repeated. Every deer or cow or sheep is always just a little different than something else..
so there is no way to pass on the results to other knives and learn how things compare.
 
Mebbe I'm on the wrong road here but my concept of knife testing is to determine if each particular blade will perform for the new owner. It sure isn't a competition or contest for me. I just wanna know if the dang thing will be dependable.

How's this for a sharpness test. Coupla weeks go I was down to visit RWWilson. We were fooling around in his shop sharpening blades. I pulled a hair from my beard, bent it over into a bow and RW shaved slivers of the hair. Thats sharp!
 
When you see a knife demonstration and it looks impressive, think about what you saw, and try to understand why what you saw worked. Sometimes it may be a magic show, once you understand how it was done you just may learn something about lady knife in the real world.
 
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