Knife destruction test question

[Bigfattyt]

Noss also altered the skinny ash, by sharpening a 1/4" off and removing the choil, thus making the edge spine much much more thicker

Grinding the edge back did not make the spine any thicker. I promise.

I will give you a knife, and a grinder and let me know if you can add any thickness to the spine by grinding the edge.

You can ruin the heat treat with a grinder.

[hardheart]

I would imagine a good prybar and maybe a hatchet would be far more suitable for "breaking out" of a building than ANY knife on the market.

Also, what would your employers think if they knew that you had a knife at work? Unless you are the boss, most employers I know of would frown heavily on having "weapons" at work and you might easily lose your job as a result.

knife = weapon

hatchet & prybar = not weapons

I actually doubt this is the case.

"edge spine" must refer to the thickness of the steel just above the edge bevel.

[Toxie]

I doubt Noss would stoop to ruining heat treat, or other dishonesty. He seems to be a real enthusiast, albeight one obsessed with just one metric LOL.

What I find amusing is that some of the OMGSWEETTOUGHOVERPRICED knife owners hold up his testing like it MEANS anything significant, or that because Noss said that x knife was poo and y knife was awesomeness.

I'm not going to pass on a BK2 or ESEE to buy a cold steel GI tanto, because I plan on using my knife as a KNIFE, not a ubertacticalurbansurvivaltool.

However if I wanted to know (for some obscure reason ) which knife was the toughest outside of any knife related use then I think I would respect his opinion.

[singularity35]

Nope. This it total BS on your part. Some of the thinnest knives I tested were many, many times tougher than their much thicker counter parts. The Bushman and the GI tanto and the CS kukri machete are very thin and lasted a very long time.The machete completely survived the tests. Thickness alone does not make a tough knife. So you don't know much of anything your are talking about.

Wow! You mean just because a piece of metal is made into a knife it now violates the laws of physics?

[demoteamone]

Wow! You mean just because a piece of metal is made into a knife it now violates the laws of physics?

Yeah LAMAO, the HT can violates the laws of universe.

[singularity35]

Yeah LAMAO, the HT can violates the laws of universe.

Oh yeh, my bad. I forgot about the magic HT.

[Bowxpress]

Grinding the edge back did not make the spine any thicker. I promise.

I will give you a knife, and a grinder and let me know if you can add any thickness to the spine by grinding the edge.

You can ruin the heat treat with a grinder.

I said (edge spine) totally different than the actual spine of the blade, and yes if you grind the edge back it will get thicker, try it and see if I'm wrong. I've been making blades for years, so yes I will take the knife and grinder, there's always room in my shop.

[bdmicarta]

I'm not trying to give you a hard time bdmicarta, but if you are concerned about being trapped in a office building, and if you are willing to keep tools on hand to help you and others escape, I don't understand why, of all tools available, would you choose a knife?

I would imagine a good prybar and maybe a hatchet would be far more suitable for "breaking out" of a building than ANY knife on the market. I could understand using a knife if you carry that knife with you all day and it's all you have with you at the time, but if you are actually going to keep tools around for a specific purpose, then why not choose the best possible tools for that job that you could reasonably have.

Also, what would your employers think if they knew that you had a knife at work? Unless you are the boss, most employers I know of would frown heavily on having "weapons" at work and you might easily lose your job as a result.

By the way, I personally would also add a small fire extinguisher and a couple of good flashlights to an emergency bag if I worked in any building that I might possibly be trapped in. And I would (and do) always carry at least one flashlight on my person at all times. A good multi-tool is also a good thing to carry, though it might be necessary to remove the blade for the workplace.

I'm following you a lot closer than you think. I read a book where a guy related a story of cutting himself out of a burning building using a Randall knife. I grabbed my CS SRK knife, a flat pry bar and a spare 2D LED maglite, put them in a spare duffel bag and stashed them by my desk. After reading about batonning knives I put a length of 2x4 in my bag. I also carry at least one big folding knife with me as well as a small flashlight.

I'm one of the company owners so nobody questions me about what I carry to work. Our business has been extremely bad for the past 18 months so I don't have spare cash to buy all of the emergency gear I could dream of. If I get any spare cash I buy a new Spyderco or Benchmade.

I have wondered what other emergency gear would be useful. I'm on the 15th floor, I wondered about having 300' of rope. I had not thought about a fire extinguisher.

[me2]

If a knife that can take a beating is the goal, look for a blade made with tough steel, properly hardened. 0.5% to 0.8% carbon is the range that will be tough and still hold an edge. Thinner blades are tougher in some cases because they can just move out of the way, like the Kukri machete. Hitting the handle with a hammer won't do much to the blade. It just flexes out of the way. It will likely break the handle scales or whatever off the tang. One of the toughest knives I have is an Old Hickory butcher knife. It's been flexed/bent 90 degrees several times and shows no problems. Not the best edge holder I have, but we all know that.

[demoteamone]

I have is an Old Hickory butcher knife. It's been flexed/bent 90 degrees several times and shows no problems.

I have the same experience with cheap machetes But, once I increase the speed applied "on the bent" the fail to come back straight, and 95% they break.
I know... lateral stress it's a bitch

[darkaether]

a thicker piece of metal will have more compression on the inside and more tension on the outside than a thinner piece under the same degree of bend.

Of course, it will also bend less under the same load, so it really depends on the application.

"thicker=tougher" is generally true for like materials, but too oversimplified to apply to all cases, and doesn't hold true at all if you are comparing dissimilar materials.

[singularity35]

a thicker piece of metal will have more compression on the inside and more tension on the outside than a thinner piece under the same degree of bend.

Of course, it will also bend less under the same load, so it really depends on the application.

"thicker=tougher" is generally true for like materials, but too oversimplified to apply to all cases, and doesn't hold true at all if you are comparing dissimilar materials.

The keyword here is generally. You might find some exceptions, but yeh, in general. Blade steels are only much differentiated by us knife nuts, but in generla, they are steel with properties not so far from each other.

[hardheart]

Wow! You mean just because a piece of metal is made into a knife it now violates the laws of physics?

nah, the issue is how the tests are evaluated. The blades/steel all 'fail' in some way as the edge deforms from either chipping or rolling, the blades bend or fracture, so the integrity of the knife is compromised in some way. But Noss is most interested in how much of the knife is left after each stage. So if the thinner blade with more ductile steel bends at a lower load during a test, he bends it back and continues. If the thicker blade with lower ductility breaks under a higher load, then it fails when the break separates a large enough portion of the handle or blade to prevent the blade from going to the next step. The steel and the volume of it still follow the fundamental forces of the universe.

It isn't an issue of physics, it is an issue of perspective and figuring out what 'question' is being asked in any form of testing along with what the answer is actually telling us.

[Big Mike]

Grinding the edge back did not make the spine any thicker. I promise.

I will give you a knife, and a grinder and let me know if you can add any thickness to the spine by grinding the edge.

You can ruin the heat treat with a grinder.

The Edge Spine refers to the thickness behind the edge and has nothing to do with the thickness of the spine of the blade.

But you are correct about not being able to add thickness to the spine of a blade by grinding the edge.




Big Mike

[JAMerolle]

Anyway guys I did not intend to start an electronic brawl but thanks for the feedback , I guess some people answered my question so thank you.

[rustyrazor]

50% of the time these threads always turn into an E-brawl... I look at it as my soap opera part of the time, i just can't wait to tune in and see what happens.

[killgar]

I'd call it a "spirited debate" .

If you have sensitive feelings you won't last long here.

[jwolf90]

My friend has a CRK Pacific... The other day watched him pound the knife into my willow tree about 5 " or so with a piece of 15 lb oak and stand on it and bounce after I asked him what he thought of Noss's tests Just saying

[singularity35]

nah, the issue is how the tests are evaluated. The blades/steel all 'fail' in some way as the edge deforms from either chipping or rolling, the blades bend or fracture, so the integrity of the knife is compromised in some way. But Noss is most interested in how much of the knife is left after each stage. So if the thinner blade with more ductile steel bends at a lower load during a test, he bends it back and continues. If the thicker blade with lower ductility breaks under a higher load, then it fails when the break separates a large enough portion of the handle or blade to prevent the blade from going to the next step. The steel and the volume of it still follow the fundamental forces of the universe.

It isn't an issue of physics, it is an issue of perspective and figuring out what 'question' is being asked in any form of testing along with what the answer is actually telling us.

I thought the "question" just was which blade can take more of a beating and survive.

[hardheart]

But we don't know how big the beatings are. There are very general ideas of how many hammer blows or how many flexes, but the applied force isn't measured. I still think it is fine in that it shows those few knives that managed to not completely fail with brittle fracture. But if you side load the blade and it bends, then you can't pry with it. And if you weren't prying with it, then why were you side loading it in the first place? So bending even without breaking would be a failure, imo. Or, sticking to knifeliness, how deep is the edge damage, since you can't cut without an edge. If you end up with a bar of steel at the end, that's fine if you need a bar of steel, but not if you need a knife.

Noss had discussed these things in the videos, but it all got overwhelmed by the internet's ability to focus, discard, and amplify. Either the overall idea of the test without details became a major factor in purchases for some, or it became a thing to crusade against with absolutely no merit in any way shape or form for others. Some got entertainment, but we can't be allowed that luxury in the serious business of tactical knives.