Edge Impact test

[Josh Crutchley]

I decided that I wanted to do a test of edge stability but it seems I did a impact test. This is NOT a test to find the best EDC steel. This is the first test I have ever done on knives. **** I didn't even own a knife till 4 months ago now I'm addicted.
I built a test rig to hold a hardened 7cr17 blank at the lanyard hole. It is positioned above a small vise to hold the test subjects. The blank is held spine down 2in(51mm) above the vise. Its 6.5in(165mm) from the pivot point to where the blank contacts the test subject. The static weight of the blank in the jig at approx. the point of contact is ~32 grams.

Manix 2 S110V 15dps .019"-.021" bte The smaller mark in the lower pic is from the blank bouncing causing a second impact.

Mule Team PD#1 15dps .018" bte

Meerkat 440c 14dps .0135" bte This wasn't as sharp as the others that's why the whole apex looks damaged.

Paramilitary 2 Maxamet 15dps .013"-.016" bte Blank seemed to slide after impact causing a wider mark. I'm also not sure what the perpendicular scratches are from cant see them with the naked eye. They might be left over from the factory grind.

Byrd Hawkbill SE 8cr13mov 23* included

I'm not really sure what to make of it other than Maxamet is tougher than I thought. The Hawkbills performance surprised me but its not apples to apples. The s110v I assumed would chip not flatten out. The Maxamet I would like to retest in the future to get a cleaner hit. Let me know if you guys like it and what I could test next. I realize I'm not very consistent with sharpening hopefully the microscope helps me improve. The test jig could use a lot of improvements and I need a better release other than pulling that block of wood out fast. I don't want to do any cardboard or rope cutting there's enough of that out there.

[tonijedi]

What these tests tell me is that no matter what the steel your balde is made of, if you bang it on a hard place the edge will be ruined.
I learnt this from real use, and that's why I like easy to sharpen steels like VG-10 and H1.

[spoonrobot]

Beautiful test construction and photos. Thank you for sharing. Very interesting result on maxamet. You should hunt down some H1 for your next test.

From one interested amateur knife tester to another, this site linked below may be helpful for you. The reviewer has quite a selection of purpose built tools for testing knives and edges. Personally I've already built an analogue for sharpness testing and am looking at recreating the edge stability jig as well. Perhaps you would be interested in such DIY construction as well: https://tacticalreviews.co.uk/?page_id=8150

[jpm2]

What these tests tell me is that no matter what the steel your balde is made of, if you bang it on a hard place the edge will be ruined.
I learnt this from real use, and that's why I like easy to sharpen steels like VG-10 and H1.

I'm pretty sure it will take a whole lot less metal removal to clean the maxamet edge up than the others.

Maxamet is mostly all strength and very little toughness. It is very resistant to denting and rolling. This will result in it having better edge stability than most other steels, up to the point that it starts cracking, then it's a different story.

Maxamet is the best medium use steel out there imo.

[Bolster]

Beautiful test construction and photos. Thank you for sharing. Very interesting result on maxamet.

Agreed. Well designed experiment. Hat's off!

[Doc Dan]

You need to try this with K390, AEB-L, LC200N, and 52100 and see what you get.

[tonijedi]

What these tests tell me is that no matter what the steel your balde is made of, if you bang it on a hard place the edge will be ruined.
I learnt this from real use, and that's why I like easy to sharpen steels like VG-10 and H1.

I'm pretty sure it will take a whole lot less metal removal to clean the maxamet edge up than the others.

Maxamet is mostly all strength and very little toughness. It is very resistant to denting and rolling. This will result in it having better edge stability than most other steels, up to the point that it starts cracking, then it's a different story.

Maxamet is the best medium use steel out there imo.

I may be wrong, as I don't have any maxamet myself, but I've read it is difficult to sharpen? I only have a sharpmaker and some basic pocket stones, I'm afraid I couldn't even deal with a damage like the one in the photo. Or am I just scared by "internet fears"?

[u.w.]

I like it, and thank you for taking the time to put it all together and share.
Very cool!

u.w.

[jpm2]

What these tests tell me is that no matter what the steel your balde is made of, if you bang it on a hard place the edge will be ruined.
I learnt this from real use, and that's why I like easy to sharpen steels like VG-10 and H1.

I'm pretty sure it will take a whole lot less metal removal to clean the maxamet edge up than the others.

Maxamet is mostly all strength and very little toughness. It is very resistant to denting and rolling. This will result in it having better edge stability than most other steels, up to the point that it starts cracking, then it's a different story.

Maxamet is the best medium use steel out there imo.

I may be wrong, as I don't have any maxamet myself, but I've read it is difficult to sharpen? I only have a sharpmaker and some basic pocket stones, I'm afraid I couldn't even deal with a damage like the one in the photo. Or am I just scared by "internet fears"?

If you have the diamond or cbn sharpmaker rods, you'll be good. They are a good idea regardless.
If you sharpen s30v, you shouldn't have any problems with maxamet.
Maxamet is very hard to grind, but easy to sharpen. I know, that's sounds odd.

[Deadboxhero]

Seems more like impact testing than edge stability.

Cool stuff

[jpm2]

Seems more like impact testing than edge stability.

Cool stuff

I agree it's impact testing, which is the least common edge stress our pocket knives encounter.

[Josh Crutchley]

Seems more like impact testing than edge stability.

Cool stuff

I might make one like the Edge on up/Bess Edge Stability Tester. I have all the parts to do it just have to sharpen all the knives.
Edit fixed title.

[JD Spydo]

All of these types of tests are good and there is some good knowledge to be gained from them. However the only truly accurate test for every day usage>> is every day usage.

And again I'm not trying to talk negative about your subject matter and to some degree I find it intriguing. But still there is no other way to determine how an edge will perform in EDC uses other than to use it in EDC cutting jobs.

But I am finding this to be an interesting thread for sure.

[tonijedi]

What these tests tell me is that no matter what the steel your balde is made of, if you bang it on a hard place the edge will be ruined.
I learnt this from real use, and that's why I like easy to sharpen steels like VG-10 and H1.

I'm pretty sure it will take a whole lot less metal removal to clean the maxamet edge up than the others.

Maxamet is mostly all strength and very little toughness. It is very resistant to denting and rolling. This will result in it having better edge stability than most other steels, up to the point that it starts cracking, then it's a different story.

Maxamet is the best medium use steel out there imo.

I may be wrong, as I don't have any maxamet myself, but I've read it is difficult to sharpen? I only have a sharpmaker and some basic pocket stones, I'm afraid I couldn't even deal with a damage like the one in the photo. Or am I just scared by "internet fears"?

If you have the diamond or cbn sharpmaker rods, you'll be good. They are a good idea regardless.
If you sharpen s30v, you shouldn't have any problems with maxamet.
Maxamet is very hard to grind, but easy to sharpen. I know, that's sounds odd.

Thank you for your answer.
I do have the diamond rods and S30V and S35VN knives.

[Josh Crutchley]

All of these types of tests are good and there is some good knowledge to be gained from them. However the only truly accurate test for every day usage>> is every day usage.

And again I'm not trying to talk negative about your subject matter and to some degree I find it intriguing. But still there is no other way to determine how an edge will perform in EDC uses other than to use it in EDC cutting jobs.

But I am finding this to be an interesting thread for sure.

I wasn't trying to test if they are good for EDC. I just wanted to do comparisons other than cut tests.

[jpm2]

All of these types of tests are good and there is some good knowledge to be gained from them. However the only truly accurate test for every day usage>> is every day usage.

And again I'm not trying to talk negative about your subject matter and to some degree I find it intriguing. But still there is no other way to determine how an edge will perform in EDC uses other than to use it in EDC cutting jobs.

But I am finding this to be an interesting thread for sure.

I agree there's no test(s) to definitively say how an edge will perform with all use. There's always something unaccounted for.
There are however tests that can simulate certain tasks that do give accurate results relating to those certain tasks.
I have a few tests I put new knives through to determine if I'll use them at work.

[jpm2]

How were the blades sharpened, and at what angles?
I don't think behind the edge thickness is relevant without knowing what angle it's derived from. It also doesn't come into play unless the damage reaches it, or the primary grind.

[Chumango]

With the light reflecting off the edges it is hard to tell if the damage was mostly dent or chip.

There will be a component of lateral force on impact because the blank has a pivot point. The ratio of vertical and lateral forces can be calculated with the dimensions you provided - the ratio of the sides of the triangle.