Chopping steel with 3V

R

ribeyemediumrare

Joined
Oct 5, 2018
Messages
111
I was testing my praetorian in 3v a bit with some random tasks and decided to see just how tough 3V really is, so I decided to try chopping this steel wire to see how the edge would hold up.
qSvcZhd.png

And here is the edge after two hard chops onto the steel holding the knife by the butt. I figured someone might find this useful even though its by no means a scientific test. I also tried it on some staples and they didn't seem to affect the edge at all and just cut in half.
VcxQqhO.jpg

I chopped the same steel wire with a Buck nighthawk (420hc) just to give me some kind of comparison, and the edge on it got a pretty good chip. It would be interesting to see how something like s35vn, m390, 3V, and s90v compares in the same test accurately controlling all the variables.
 
Good stuff! I always love seeing testing like this. Some may consider it abuse but I do like to know how certain types of steels hold up to these sort of things. Thanks for testing your awesome knife in a manner most wouldn't :)
 
If you are going to take the time to do some abuse you might as well video it. A picture and short explanation doesn't do much.
 
And another thing....successfully chopping through nails and such is much more dependent upon geometry rather than steel type. If the steel type (regardless of what it is) is sufficiently hardened, then a thick geometry can perform these sort of chops.

I other words, you could take 1050, hardened and tempered well, with thick enough geometry, and have it chop through a nail (staple, whatever) without any edge damage.

That’s why the brass rod test is more or less useless to us makers. It shows that the steel was hardened “decently enough”, but tells us absolutely nothing about its potential.

Nothing against you or your efforts. Just wanted to clarify.

To sum up even further....there is no way I would ever want myself or anyone else to chop through a 16 penny nail with a 63HRC 52100 knife that has a presharpened edge width of 0.005”. It will cut meat till the cows come home without needing a touch up. But try chopping through a nail with it, there will be blood (so to speak). I trust you get my drift.
 
Cobalt said:
If you are going to take the time to do some abuse you might as well video it. A picture and short explanation doesn't do much.
Click to expand...
I did this on a whim just to see what would happen and took a pic last minute, I figured it was better then nothing. I think If I was going to record somekind of testing I would make it a bit more scientific
 
samuraistuart said:
And another thing....successfully chopping through nails and such is much more dependent upon geometry rather than steel type. If the steel type (regardless of what it is) is sufficiently hardened, then a thick geometry can perform these sort of chops.

I other words, you could take 1050, hardened and tempered well, with thick enough geometry, and have it chop through a nail (staple, whatever) without any edge damage.

That’s why the brass rod test is more or less useless to us makers. It shows that the steel was hardened “decently enough”, but tells us absolutely nothing about its potential.

Nothing against you or your efforts. Just wanted to clarify.

To sum up even further....there is no way I would ever want myself or anyone else to chop through a 16 penny nail with a 63HRC 52100 knife that has a presharpened edge width of 0.005”. It will cut meat till the cows come home without needing a touch up. But try chopping through a nail with it, there will be blood (so to speak). I trust you get my drift.
Click to expand...
I'm not familiar with the brass rod test. I was also under the impression that hardness would make the edge more prone to chipping vs rolling over. When you say geometry are you referring to bevel angle or edge thickness? I believe this blade did well considering the edge thickness is around 0.023 but like I said this wasn't really mean to be scientific or prove anything, more of a take what you will out of it test. What are some good ways you would test blade toughness without destroying it? Edge retention seems to be pretty easy to test but toughness not as much.
 
The brass rod test is when a brass rod is used to test how well an edge flexes against it. Some think it is supposed to be used (as in your test) that you’re supposed to chop through it. Neither shows anything of what the steel is capable of. These tests only show what the geometry is capable of. That is why they are useless. What you are saying is that 3v succeeded (with the knife you used) and the 420 failed (with the knife you used). All I am saying is that for an inference to be made, steel vs steel, which is what you claimed, is that the geometry MUST be identical and the hardness of both steels MUST be identical. (The heat treatment used to get identical hardness is also a variable....but let’s leave that aside
For this discussion....as differing heat treats at the same hardness will get way too complicated for this sub forum). I understand you’re not a maker, and I’m just saying the facts. Not trying to step on toes or anything like that. All I am saying is that apples need to be compared to apples.

And BTW.... 0.023” at the edge (or edge shoulders) is very very thick, unless it’s a blade designed for chopping. Waaaaay too thick for a pocket knife. (Another topic for another discussion). They make pocket knives thick for the masses/warranty.

When I say “geometry” I am talking mostly about edge thickness...which is a function of the grind. Usually this is measured at the edge prior to sharpening, or at the edge shoulders after sharpening. Regardless, the premise stands. Chopping through hard material is primarily a function of how thick the steel is, not its comp or heat treatment (provided the heat treatment was decent enough .... as in .... is it decently hard?). This is the whole point. Chopping through hard nails and such is a “parlor trick” that is simply based upon geometry and a “decent enough heat treat”.

Again....you would NEVER attempt to chop through a nail with a thin, Nakiri 52100 (or whatever steel), hardened “decently enough” (60hrc+) that was ground thin, like the knife is called for. No way. You would have catestrophic failure doing so. Does that mean the steel, knife, or heat treatment is off? No way! It means you abused it!
It means nothing about the steel or heat treatment. It means that the geometry was too thin for the abuse you gave it.

I can’t make it more simple to understand, and I hope and trust
You get this. Again, not an attack by ANY MEANS AT ALL. Just trying to educate.
 
How do you test steels and toughness? There are technical methods. CATRA and the like. Best method? Use as intended. Chopping through nails and such is not “as intended”. You could outperform 3v with 420hc doing such a test easily...thicken the edge geometry.
 
samuraistuart said:
The brass rod test is when a brass rod is used to test how well an edge flexes against it. Some think it is supposed to be used (as in your test) that you’re supposed to chop through it. Neither shows anything of what the steel is capable of. These tests only show what the geometry is capable of. That is why they are useless. What you are saying is that 3v succeeded (with the knife you used) and the 420 failed (with the knife you used). All I am saying is that for an inference to be made, steel vs steel, which is what you claimed, is that the geometry MUST be identical and the hardness of both steels MUST be identical. (The heat treatment used to get identical hardness is also a variable....but let’s leave that aside
For this discussion....as differing heat treats at the same hardness will get way too complicated for this sub forum). I understand you’re not a maker, and I’m just saying the facts. Not trying to step on toes or anything like that. All I am saying is that apples need to be compared to apples.

And BTW.... 0.023” at the edge (or edge shoulders) is very very thick, unless it’s a blade designed for chopping. Waaaaay too thick for a pocket knife. (Another topic for another discussion). They make pocket knives thick for the masses/warranty.

When I say “geometry” I am talking mostly about edge thickness...which is a function of the grind. Usually this is measured at the edge prior to sharpening, or at the edge shoulders after sharpening. Regardless, the premise stands. Chopping through hard material is primarily a function of how thick the steel is, not its comp or heat treatment (provided the heat treatment was decent enough .... as in .... is it decently hard?). This is the whole point. Chopping through hard nails and such is a “parlor trick” that is simply based upon geometry and a “decent enough heat treat”.

Again....you would NEVER attempt to chop through a nail with a thin, Nakiri 52100 (or whatever steel), hardened “decently enough” (60hrc+) that was ground thin, like the knife is called for. No way. You would have catestrophic failure doing so. Does that mean the steel, knife, or heat treatment is off? No way! It means you abused it!
It means nothing about the steel or heat treatment. It means that the geometry was too thin for the abuse you gave it.

I can’t make it more simple to understand, and I hope and trust
You get this. Again, not an attack by ANY MEANS AT ALL. Just trying to educate.
Click to expand...
No worries I'm completely with you about geometry, thats why I stated that this wasn't meant to be a scientific test with controlled variables but more so just for fun. It would be good to see an actual standardized toughness test conducted on different blade steels. A more realistic explanation for my little experiment was to see what the overall blade package can handle so I know its limits in actual tasks. BTW I know makers have much thinner expectations for edge thickness and that production knife are made thicker then needed, when I said that 0.023 is decent I'm comparing it to other production knives that people generally consider to be much more slicey (think sebenza or Pm2), considering how thick and overbuilt this knife is and many people claiming it can't cut the edge is thinner then most would expect on this type of knife, especially when compared to an xm18 that I believe is roughly 0.040 behind the edge.
 
ribeyemediumrare said:
I did this on a whim just to see what would happen and took a pic last minute, I figured it was better then nothing. I think If I was going to record somekind of testing I would make it a bit more scientific
Click to expand...

For many reasons it is hard to make hand testing very scientific. Just changing the angle of your hand can make a big difference in damage to the edge. Edge geometry makes a big difference as well. Just video tape it and keep it fun for yourself. Besides, videos are fun to watch
 
samuraistuart said:
And BTW.... 0.023” at the edge (or edge shoulders) is very very thick, unless it’s a blade designed for chopping. Waaaaay too thick for a pocket knife. (Another topic for another discussion). They make pocket knives thick for the masses/warranty.

When I say “geometry” I am talking mostly about edge thickness...which is a function of the grind.
Click to expand...

As you can see: I'm new to the forum so please forgive me if this is a foolish question. When you say "edge shoulder" do you mean just the thickness of the blade immediatly after the microlevel? So with a full flat grind you would have a consistently thickening edge/edge shoulder as you sharpen it, right? Thanks for the clarification!
 
StoneAndSteel said:
As you can see: I'm new to the forum so please forgive me if this is a foolish question. When you say "edge shoulder" do you mean just the thickness of the blade immediatly after the microlevel? So with a full flat grind you would have a consistently thickening edge/edge shoulder as you sharpen it, right? Thanks for the clarification!
Click to expand...

The blade profile is a primary grind. The edge you cut into the blade is the secondary grind. The transition from the edge to the blade flat section is the shoulder. See shoulders below
Knife-sharpening.png
 
Thanks to Cobalt for the help here in this thread. Yes, when you sharpen a knife, the edge shoulder is that junction at the very top of the actual edge bevel that transitions into the blade grind. If I was better at illustrations, and not on an IPhone, I think I could make this very clear. Round off that shoulder...makes for even better performance! Lots of variables to consider in cutting ! No doubt about it. Geometry is king. This fact is undebatable. Geometry is king. Then.....a solid heat treatment. You may be surprised to know it, but it’s true. If the steel is a hardenable knife quality steel, the heat treatment it received is way more important than the actual steel type. Just facts my friends! And a distant third in the race is the actual steel itself. So to recap simply, what makes a good cutting instrument?

1. Geometry. I can slice you up quick with the lid of a tin can!

2. Heat treatment. If I had a way of making that tin can harder....I could cut you for a longer period.

3. Actual steel composition. The beter the steel, the better I can harden it, the longer I can cut with it

I think this is a simple way to get my point across!

Stay sharp! Thanks for the thread! And thanks for understanding where makers come from! Not here to attack, or negate, or anything like that. There is a lot of mis and dis info. Just trying to help educate. And I am by no means some sort of authority or claim to be. Always willing to learn!!
 
So going from the spine to the cutting edge you have the primary grind, shoulder, then the secondary grind where the magic happens. If you have a back bevel you would have (from spine to cutting edge) the primary grind, shoulder, back bevel, shoulder, and then secondary grind?

This may be a question too deep for my current level of understanding... But there's only one way to learn, right? Is there a rule of thumb with respect to what angle you would use on your secondary bevel based on your primary? My understanding is that for hard use edges (batoning and such) you generally use a more obtuse angle simply based on how it is going to be used. But is there a mathematical formula or is it going to be based on the maker/manufactures proprietary "science?"
 
It will be based on blade geometry, thickness, hardness and steel type which varies toughness to go with a good HT. So there is no standard. On a tough steel you can go steeper angles. However if that tough steel is to soft the thin edge will easily deform.
 
A hard steel should be able to cut a soft wire. But reduce that edge to a lower point and it will take damage on even soft wire. OP is asking about 3V. 3v is tough. I am pretty sure that there are videos of miller bros blades cutting steel. So the answer is yes with proper design of blade and edge geometry
 
OP, if you want to see what 3V with a great (I would say the best) heat treat can do, watch this:
.
And all other videos on Nathan's channel ;)
Cheers!
 
You must log in or register to reply here.
Back
Top