2 Spydercos, some old jeans and a roll of shop towels!

[Ned]

Hi Ned, interesting results. I am curious about the edge on the se delica...is that a user? Do you sharpen it yourself? Does it have an equal level of sharpness as the pe? I keep my se salts extremely sharp and I would not expect them to behave the way your delica did. I use them often and they fly through skin, flesh and small bone. (fish) I have never cut jeans and towels with them though. :) I was surprised because given equal levels of sharpness I definitely would not have expected the results you got.

It could be a function of the FFG versus the Saber Grind..

[Michael Janich]

Dear Ned:

Thanks again for sharing your results.

If you dig around on the forums or have read any of my articles in which I address serrated edges for defensive use, you'll see that I'm a firm believer in plain edges with great edge geometry. In ballistic cutting (where the blade is in motion before it makes contact with the target) on clothed targets, most serrated edges tend to grab the cloth and move it over the underlying target. Although they still cut, the edge does not get access to penetrate the underlying target because the material is moving with it. Plain edges with good edge geometry cut cleaner and don't move the material. As such, the material gets cut cleanly and the edge is free to do its work on the underlying target.

I've been teaching this for years, but the "logical" assumption has always been that serrated edges will bit deeper. It's great to see someone actually do objective testing and come to the same conclusion. I've done this test many, many times--including with a ballistic pendulum to remove the human factor. I always get the same results.

Thanks again for your empirical efforts and for sharing your results.

Stay safe,

Mike

[Surfingringo]

Dear Ned:

Thanks again for sharing your results.

If you dig around on the forums or have read any of my articles in which I address serrated edges for defensive use, you'll see that I'm a firm believer in plain edges with great edge geometry. In ballistic cutting (where the blade is in motion before it makes contact with the target) on clothed targets, most serrated edges tend to grab the cloth and move it over the underlying target. Although they still cut, the edge does not get access to penetrate the underlying target because the material is moving with it. Plain edges with good edge geometry cut cleaner and don't move the material. As such, the material gets cut cleanly and the edge is free to do its work on the underlying target.

I've been teaching this for years, but the "logical" assumption has always been that serrated edges will bit deeper. It's great to see someone actually do objective testing and come to the same conclusion. I've done this test many, many times--including with a ballistic pendulum to remove the human factor. I always get the same results.

Thanks again for your empirical efforts and for sharing your results.

Stay safe,

Mike

Thanks for the explanation. Makes sense. I did well in physics and I'm usually pretty good at guessing the results of tests like this but I guess I had this one wrong.

I think an important distinction is the "ballistic" cutting you mentioned. For example, I know that if I have a tough skinned fish then a serrated spyderco will penetrate (and cut) on a pull cut with much less pressure than a plain edge. The results might be different if I was swinging the knife at the fish, I don't know. The other important distinction is that the skin doesn't move with the cut like clothing. The clothing seems to be the key variable that I didn't add to my physics equation. So I still think it would be functional to use a serrated edge for self defense but only if you are attacked by a naked maniac.

[rodloos]

Thanks for the explanation. Makes sense. I did well in physics and I'm usually pretty good at guessing the results of tests like this but I guess I had this one wrong.

I think an important distinction is the "ballistic" cutting you mentioned. For example, I know that if I have a tough skinned fish then a serrated spyderco will penetrate (and cut) on a pull cut with much less pressure than a plain edge. The results might be different if I was swinging the knife at the fish, I don't know. The other important distinction is that the skin doesn't move with the cut like clothing. The clothing seems to be the key variable that I didn't add to my physics equation. So I still think it would be functional to use a serrated edge for self defense but only if you are attacked by a naked maniac.

Oh, the visual imagery! :D I wouldn't want to be the naked maniac getting close to a SE (or any) blade.

[Ned]

Thanks Again Mr. Janich, I have found these tests very interesting and enlightening from an experiential standpoint. I think that anyone who has ever considered the martial application of a knife would benefit from doing something like this themselves, to gain that experience. If the only thing that one cuts in training is air, or slow speed drills with a partner using a trainer, you miss out on an important dimension of blade dynamics.

[Ned]

Thanks for the explanation. Makes sense. I did well in physics and I'm usually pretty good at guessing the results of tests like this but I guess I had this one wrong.

I think an important distinction is the "ballistic" cutting you mentioned. For example, I know that if I have a tough skinned fish then a serrated spyderco will penetrate (and cut) on a pull cut with much less pressure than a plain edge. The results might be different if I was swinging the knife at the fish, I don't know. The other important distinction is that the skin doesn't move with the cut like clothing. The clothing seems to be the key variable that I didn't add to my physics equation. So I still think it would be functional to use a serrated edge for self defense but only if you are attacked by a naked maniac.

You never know! It could happen! :eek:

[UpDok]

It is fascinating to me that the serrated edge Delica did not cut better than the plain edge Delica, instead the performance was worse than the plain edge knife in this application.

This begs the question: Would a serrated edge hawk bill such as the Civilian, Matriarch, or Tasman Salt tend to bounce or move with cloth instead of making dramatic cuts? I thought the dramatically serrated hawk bills, especially the Civilian & Matriarch were designed for slash cuts. Perhaps the hawk bill curve radically changes the cutting dynamic.

[Ned]

You are probably going to have to ask Mr. Janich about that...I'm not going to subject my Civilian to that kind of abuse. :confused: That is an excellent question in my book and I would love to know what others who may have knowledge on the subject think..

[chuck_roxas45]

There's a big difference between causing more damage and damaging things that actually make the attacker stop based on reliable, physiological effects.

Stay safe,

Mike

You'll get no argument from me on that Mr. Janich. :)

[Michael Janich]

This begs the question: Would a serrated edge hawk bill such as the Civilian, Matriarch, or Tasman Salt tend to bounce or move with cloth instead of making dramatic cuts? I thought the dramatically serrated hawk bills, especially the Civilian & Matriarch were designed for slash cuts. Perhaps the hawk bill curve radically changes the cutting dynamic.

Sorry for the slow response... I'm at the SOFIC special operations trade show sharing Spyderco knives with the specops community.

The difference with hawk bills is the direction of the cutting action. Typically, hawk ills cut by penetrating with the point and cutting back toward the heel of the blade. Other blade designs make contact with the heel first and cut toward the point. The latter action is what causes clothing to move and dissipates the force of a cut. Penetrating with the point anchors the material to the target and starts the cut with the blade in the target. The target gets cut first and the material stays in place, getting cut with it.

Reverse S blades offer the best of both worlds, filling the void at the heel while offering the power of a hawksbill at the point.

I hope this helps.

Stay safe,

Mike

[UpDok]

Thank you Sir for the info. It does help.
It makes sense that the reverse-S curve makes the difference in serrated hawk bill design.

[Dr. Snubnose]

Ned...It starts first with cutting your jeans...then your leather jackets...and before you know it you are buying meat lol.....I wouldn't think to carry any knife for SD without testing it on meat....That said....Get a second job now!!!!....The Centofante IV: I have tested repeatedly and it did very quite well in the tests IIRC it was on par with a PE Endura in results. Hope that helps....Doc :)

[rodloos]

Great to see you stopping back in Dr. Snubnose!

[JNewell]

Edited - question answered.

[Ned]

Ned...It starts first with cutting your jeans...then your leather jackets...and before you know it you are buying meat lol.....I wouldn't think to carry any knife for SD without testing it on meat....That said....Get a second job now!!!!....The Centofante IV: I have tested repeatedly and it did very quite well in the tests IIRC it was on par with a PE Endura in results. Hope that helps....Doc :)

Yes, I have been eyeballing my old Wilson Leather jacket with the broken zipper...come to think of it, my ex-wife bought that for me...hhmmm! :D

[anagarika]

Ned,

Thank you for the test and sharing. On serrated vs plain, here is a meat test that seems to have different result:
http://m.youtube.com/watch?rl=yes&v=LUR ... l=en&guid=

IIRC, he said the PE was hand sharpen and the SE was factory.

Mr. Janich, not to dispute your tests, but need to understand what us the factor contributing to the result. Perhaps you can share some insights?

Regardless, my EDC is PE as I dislike the hassleof touching up SE.

[Ned]

Ned,

Thank you for the test and sharing. On serrated vs plain, here is a meat test that seems to have different result:
http://m.youtube.com/watch?rl=yes&v=LUR ... l=en&guid=

IIRC, he said the PE was hand sharpen and the SE was factory.

Mr. Janich, not to dispute your tests, but need to understand what us the factor contributing to the result. Perhaps you can share some insights?

Regardless, my EDC is PE as I dislike the hassleof touching up SE.

In the video you will take note that the serrated edge blade had quite a profound recurve, the results would have been more interesting if the blade shapes were the same. It would be interesting to test a PE Endura and perhaps an Ulize! or a FFG Police and an Ulize. Interesting concepts though, interesting video; thanks for linking it.

[anagarika]

I guess you're right. The recurve might be changing the dynamics of the cut.

The author also tested pacific salt.

Again, thanks for the test & thread!

[Surfingringo]

I guess you're right. The recurve might be changing the dynamics of the cut.

The author also tested pacific salt.

Again, thanks for the test & thread!

How did the pacific salt do? About the same?

[anagarika]

In the salt video, he compared 3 knives: one PE (dull, struggle to cut rope), one SE, one PE sharp. All won (i.e. Cut deeply). However he didn't use jeans like the Voyager test and only saran wrapped the meat.

I can't conclude anything, as I'm guessing the dull PE will slip/skid more on jeans if he used, but he didn't.

FWIW, cut with force anytime it's neede like what Chuck said.