Are you over Super Steels?

[BluntCut MetalWorks]

Edge geometry is crazily important, next is the blade profile, third is ergonomic. So it makes sense to start from the apex, give best care/sharpening & sculpturing. Bevel face length and bevel shoulder thickness need to optimize for given tasks (in full consideration of cutting material & technique/requirement)... so on to macro level.

Bodog, excellent quick delineation between usage goal/need: wear resistance & high apex stability:thumbup:

52100/1095/W2/etc... are fairly high carbide(mostly cementite) volume. While 3V (0.8%C) has lower carbide volume but mainly Vanadium Carbide (1-2um in size), actually provide as much or better wear resistance. Plus it has quite a bit of free-Cr ~7% for corrosion resistant (a little over half way to stainless).

All clean steels are high tech to me. A clean steel with high alloy & other non-Fe elements (lower Fe balance) is like an artist canvas with 'outlines' designated for certain arts, and given 'pre-mixed' colors palette. For the Elmax blade above, I had to break the 'outlines'/primary-carbides (that's right, a long soak at 2200F) and jumbled up 'pre-mixed'/MxCy tendencies. Essentially, as stated by others/posts, super performance is super. Knife makers/mfg need to use whatever steels to accomplish that super performance. A wider range of utility is better than narrow/single-task performer. Also bang/buck ratio is part of performance equation.

 

[Ankerson]

Edge geometry is crazily important, next is the blade profile, third is ergonomic. So it makes sense to start from the apex, give best care/sharpening & sculpturing. Bevel face length and bevel shoulder thickness need to optimize for given tasks (in full consideration of cutting material & technique/requirement)... so on to macro level.

.

Exactly right.

Thin generally will give the best overall performance as long as the geometry isn't too thin for the given tasks then it needs to be adjusted as needed.

Start getting really thin in the .005" range and under the edge geometry is critical and needs to be adjusted as needed for the tasks the knife will see. The good thing is when the blade geometry is that thin it's going to perform very well performance wise so adjusting the edge geometry to stabilize the edge won't have as much of an effect on cutting performance because the blade geometry is so thin it is going to cut extremely well.

The reason why straight razors and double edge razor blades have the geometry and cut as well they do as an example. The blade geometry is extremely thin while the actual edge geometry is not really low, more in the normal 10 to 15 DPS range or higher depending. So we have extremely thin blade geometry with edge geometry adjusted as needed to keep the edge stable.

 

[BluntCut MetalWorks]

Optimal/task physics for certain edge bevel can be complicated, much more than just thin and thinner as better. For highly adhesive and compressive material, yes thinness translate to psi easily exceed material fracture point. For stiff material, correct amount of wedging would stretch the material, giving the apex an easy task of fracture the stretched material at low psi. At the same time, preserving the apex. For the former case (super thin, more binding), the apex works harder, hence suffer more wear and damage.

For given range of tasks: A good blade material (steel + ht) allows you to tailor/sculpture edge geometry more closely to an optimized structural (engineering) requirement. When a blade material wouldn't allow such geometry tailoring, well one made a poor choice of blade material. 'Structural' is a shape consisting blade material. Not only, the bulk of this material is the steel Matrix, the matrix also the base for keeping carbides in place. So geometry is mostly build on matrix, hence matrix need to be a strong & tough as possible. Carbides trade in matrix toughness & strength for added wear resistance, thereby preclude certain optimal geometries for required tasks.

Exactly right.

Thin generally will give the best overall performance as long as the geometry isn't too thin for the given tasks then it needs to be adjusted as needed.

Start getting really thin in the .005" range and under the edge geometry is critical and needs to be adjusted as needed for the tasks the knife will see. The good thing is when the blade geometry is that thin it's going to perform very well performance wise so adjusting the edge geometry to stabilize the edge won't have as much of an effect on cutting performance because the blade geometry is so thin it is going to cut extremely well.

The reason why straight razors and double edge razor blades have the geometry and cut as well they do as an example. The blade geometry is extremely thin while the actual edge geometry is not really low, more in the normal 10 to 15 DPS range or higher depending. So we have extremely thin blade geometry with edge geometry adjusted as needed to keep the edge stable.

 

[Twindog]

Knives are deceptively complex.

Optimal edge geometry is going to depend on the edge angle and the shoulder width of the edge (which in turn depends on blade geometry).

Edge angle and shoulder width that are best for any given task depend on the strength and toughness of the steel.

Strength and toughness of the steel depend on steel alloy, steel processing (such as powder vs ingot) and heat treat.

Then you will also want a certain degree of wear resistance, which depends on edge geometry, steel alloy and heat treat.

What you end up with is an almost infinite number of variables and will be optimal for any given task. And we have an almost infinite number of combinations for the tasks we use our knives for.

 

[bodog]

Essentially, as stated by others/posts, super performance is super. Knife makers/mfg need to use whatever steels to accomplish that super performance. A wider range of utility is better than narrow/single-task performer. Also bang/buck ratio is part of performance equation.

:thumbup:

 

[Ankerson]

Optimal/task physics for certain edge bevel can be complicated, much more than just thin and thinner as better. For highly adhesive and compressive material, yes thinness translate to psi easily exceed material fracture point. For stiff material, correct amount of wedging would stretch the material, giving the apex an easy task of fracture the stretched material at low psi. At the same time, preserving the apex. For the former case (super thin, more binding), the apex works harder, hence suffer more wear and damage.

For given range of tasks: A good blade material (steel + ht) allows you to tailor/sculpture edge geometry more closely to an optimized structural (engineering) requirement. When a blade material wouldn't allow such geometry tailoring, well one made a poor choice of blade material. 'Structural' is a shape consisting blade material. Not only, the bulk of this material is the steel Matrix, the matrix also the base for keeping carbides in place. So geometry is mostly build on matrix, hence matrix need to be a strong & tough as possible. Carbides trade in matrix toughness & strength for added wear resistance, thereby preclude certain optimal geometries for required tasks.

I was simplifying it basically for general terms.

I am more than are aware of the other factors that also contribute to performance, they all have to work together.

 

[JR88FAN]

Actually you are wrong.

I personally have stated that thin and hard is generally better when it comes to edge retention and my testing backs that up. The thinner the geometry is the higher the HRC hardness needs to be.

Cliff on the other hand more than a few times and argued with me and others more times that I can remember that HRC hardness doesn't matter.

He blew up the Spyderco forum more times that I can count with that freaking BS.

He flip flops around depending on what his current agenda is way too much or depending on which one of his few knife maker buddies he wants to push that week. There aren't many these days so he really pushes them. That or whatever kick he is on that day or whatever argument he can start taking the opposite side and then flip flop to the other side whenever.

That's the reason why he has been banned on every knife forum on the internet except one, he argues just to argue and stir things up, starts conflicts just to start conflicts. That and he tries to tell knife makers how to do what they do, ones that have been making knives for decades arguing with them.

Such as: 20CV/M390 S90V ZDP-189

The rest of your post sums up the issue not just with the person you are referring to, but anyone getting that deep into something on a whole.
You start to go in circles and forget which way is up...or sharp....point is, there is really no useful-to-everyone (maybe anyone) info there.

Jim, based on your experience, what would you have to do to 52100 so it could hold an edge like 20CV?
Is this even possible? If so, there must be a major trade-off...
I am having a difficult time with 52100 going through 300ft of dirty cardboard and then still be able to slice printer paper.
That has never been my experience with that steel..

 

[Ankerson]

Such as: 20CV/M390 S90V ZDP-189

The rest of your post sums up the issue not just with the person you are referring to, but anyone getting that deep into something on a whole.
You start to go in circles and forget which way is up...or sharp....point is, there is really no useful-to-everyone (maybe anyone) info there.

Jim, based on your experience, what would you have to do to 52100 so it could hold an edge like 20CV?
Is this even possible? If so, there must be a major trade-off...
I am having a difficult time with 52100 going through 300ft of dirty cardboard and cutting printer paper.
That has never been my experience with that steel..

Personally I dunno, don't think it would be possible based on what I know unless the variables where seriously lopsided to favor 52100 and that would have to be done on purpose.

Once would have to handicap 20CV really bad in a number of ways.

 

[bodog]

Such as: 20CV/M390 S90V ZDP-189

The rest of your post sums up the issue not just with the person you are referring to, but anyone getting that deep into something on a whole.
You start to go in circles and forget which way is up...or sharp....point is, there is really no useful-to-everyone (maybe anyone) info there.

Jim, based on your experience, what would you have to do to 52100 so it could hold an edge like 20CV?
Is this even possible? If so, there must be a major trade-off...
I am having a difficult time with 52100 going through 300ft of dirty cardboard and then still be able to slice printer paper.
That has never been my experience with that steel..

pictures are worth 1000 words. I just got done doing this. Here's 330 cuts into cardboard. Obviously I could cut more if I wanted. One stack is tripled up double ply. 4 stacks are just double ply. Still sharp enough to cut myself and draw cut printer paper. I did not touch the edge at all since the last use. This is for real. Believe it or not. This is coming off the +/- 300 ft of cardboard, among other things. Obviously this isn't 300 ft. More like 150? Most cuts were between 3 and 6 inches long on double walled cardboard. 30 cuts were straight up six inches on tripled up double wall. Take from it what you want.

And the results

 

[bodog]

And one more round. 240 cuts into double walled cardboard. 480 cuts single. Average 4 inches per cut. 160 ft, give or take a few inches. Add this to the 300 feet and the total from the other round I didn't bother to figure out. I'm guessing around 600 to 700 feet of single walled cardboard. Still sharp enough to slice printer paper and now my thumb, damn it.

 

[Surfingringo]

Such as: 20CV/M390 S90V ZDP-189


Jim, based on your experience, what would you have to do to 52100 so it could hold an edge like 20CV?
Is this even possible? If so, there must be a major trade-off...
I am having a difficult time with 52100 going through 300ft of dirty cardboard and then still be able to slice printer paper.
That has never been my experience with that steel..

Personally I dunno, don't think it would be possible based on what I know unless the variables where seriously lopsided to favor 52100 and that would have to be done on purpose.

Once would have to handicap 20CV really bad in a number of ways.

Here's what I think would be interesting. Grind something like s110v as thin as you could to handle a give task without edge failure. Then grind something like 52100 as thin as you can to handle the same task. If 52100 could accomplish a given cutting task with a thinner geometry then it would be interesting to see how the two knives would compare in edge retention. It might look at first glance to be an apples to oranges comparison but it's really not. You'd just be comparing the most efficient grind of two different steels for a given task.

Of coure, figuring out just how thin you could go respectively with the two steels for the same work would be the hard part.

 

[bodog]

And last round for the night. Some wood. Don't know what kind it is but I sliced up one piece, made chops into another with hard twists on the way out, and then stabbed in in and pried straight out. Still cleanly slices printer paper. You can say what you want, but don't question bluntcut's heat treatment of some good steel.

For this knife that was an easy display, not even really a test. My actual test of this knife is over in the testing and review section. THAT was a test (http://www.bladeforums.com/forums/s...lworks)-52100-Hard-Use-(Updated-with-results)) Whatever tonight's demonstration may be to other knives, it was easy for this one. The edge looks exactly the same as it did before the demo. That's called apex stability.

The spots reflecting are not the edge. That's just paper. There are no rolls, dents, fractures or anything I can feel. That was just paper fiber still stuck to the edge. I did dent the tip by stabbing it straight into a piece of ceramic tile. I couldn't help myself.

 

[Stays Sharp]

After reading more of your posts... You're not a Cliff Stamp dummy I realize. I was wrong Bodog, good for you. :foot:

 

[bodog]

After reading more of your posts... You're not a Cliff Stamp dummy I realize. I was wrong Bodog, good for you. :foot:

 

[Ankerson]

Here's what I think would be interesting. Grind something like s110v as thin as you could to handle a give task without edge failure. Then grind something like 52100 as thin as you can to handle the same task. If 52100 could accomplish a given cutting task with a thinner geometry then it would be interesting to see how the two knives would compare in edge retention. It might look at first glance to be an apples to oranges comparison but it's really not. You'd just be comparing the most efficient grind of two different steels for a given task.

Of coure, figuring out just how thin you could go respectively with the two steels for the same work would be the hard part.

The steels are just too far apart really in edge retention to do that, one would have to handicap S110V a lot to even bring them close, the knives wouldn't even be close to the same.

Take 2 steels that are closer in performance and start playing with the geometries and yeah it can get interesting.

 

[Stays Sharp]

Nah I really meant that. As an apology.

 

[Surfingringo]

The steels are just too far apart really in edge retention to do that, one would have to handicap S110V a lot to even bring them close, the knives wouldn't even be close to the same.

Take 2 steels that are closer in performance and start playing with the geometries and yeah it can get interesting.

Wouldn't we have to see what the actual difference in thickness/geometry is and define what kind of work we are talking about first before we say that? For the sake of making an extreme argument, what if one steel could be ground 50% thinner than another and still withstand a given work load without damage? Wouldn't that make a significant difference in edge retention? I don't have the answers, I just think these are interesting questions.

 

[bodog]

Wouldn't we have to see what the actual difference in thickness/geometry is and define what kind of work we are talking about first before we say that? For the sake of making an extreme argument, what if one steel could be ground 50% thinner than another and still withstand a given work load without damage? Wouldn't that make a significant difference in edge retention? I don't have the answers, I just think these are interesting questions.

Things can be guessed. I'd hazard to say that S110V absolutely could not do what I've done with 52100 from bluntcut over the past week or so unless it was at least 25 to 50% thicker at the spine and double the edge shoulder thickness with half the cutting efficiency. That's just a guess. If someone wants to provide a sample blade to test I'd happily do it. I truly don't believe that S110V could do what this knife is capable of at anywhere near the same thickness, not from a utilitarian standpoint.

 

[drebs]

Exactly right.

Thin generally will give the best overall performance as long as the geometry isn't too thin for the given tasks then it needs to be adjusted as needed.

Start getting really thin in the .005" range and under the edge geometry is critical and needs to be adjusted as needed for the tasks the knife will see. The good thing is when the blade geometry is that thin it's going to perform very well performance wise so adjusting the edge geometry to stabilize the edge won't have as much of an effect on cutting performance because the blade geometry is so thin it is going to cut extremely well.

The reason why straight razors and double edge razor blades have the geometry and cut as well they do as an example. The blade geometry is extremely thin while the actual edge geometry is not really low, more in the normal 10 to 15 DPS range or higher depending. So we have extremely thin blade geometry with edge geometry adjusted as needed to keep the edge stable.

Jim, I've read tons of your post and have been looking for an answer where the topic is alluded to here. This has been a question that's been on my mind for awhile now and it's mostly summed up with the excerpt quoted. The question that remains is how thin do you want to go if your not going to get the behind the edge thinned, as well as how thick could you stay and still see marketable improvements over the factory edge. As I have a GB(all purpose), M4 mule(dressing), Manix 2 s110v(all purpose), Zdp stretch(bird cleaning), VG-10 endura (slicer), Chaparral cts-xph (EDC), Militray S30V.

My question comes in the form of having a Gayle Bradley M4 & Mule M4, Where I want to take the Mule thin enough to get super busy dressing game, bones and all without going too thin that i can't get into some bone .015 to conservative?.. .005 too liberal givin the task? And on the GB a good mix of thin enough to get rough with it, obviously not a chipper or prybar but see the heaviest use of the knives mentioned.

Then with my Manix 2 s110v.. a good range of thinning behind the edge or if you have a link to refer. Obviously I'm not going to spend $50 to get all these thinned. So the one's a dont i will be using the edge pro/Sharpmaker with Congress Mold Master's 400-600 grit on the working knives. And obviously higher grits on the slicers.

So I'm just trying to find some rec's on edge thinness on the mentioned knives mainly the M4 and S30V, As well as how thin dps to take the other's im not going to send off for thinning without getting too wide at the shoulders.

Sorry if this post is to hefty I have looked many places for these anwsers have seen where M4 take take a .005 and still kick ass and take rougher jobs.

Again thanks for the wisdom and knowledge being shared to people like me would want to learn and are learning the right way and not from the people who see things in black and white I've learned there's no such thing with knives way too many factors.

 

[JR88FAN]

And last round for the night. Some wood. Don't know what kind it is but I sliced up one piece, made chops into another with hard twists on the way out, and then stabbed in in and pried straight out. Still cleanly slices printer paper. You can say what you want, but don't question bluntcut's heat treatment of some good steel.

For this knife that was an easy display, not even really a test. My actual test of this knife is over in the testing and review section. THAT was a test. Whatever tonight's demonstration may be to other knives, it was easy for this one. The edge looks exactly the same as it did before the test. That's called apex stability.

The spots reflecting are not the edge. That's just paper. There are no rolls, dents, fractures or anything I can feel. That was just paper fiber still stuck to the edge. I did dent the tip by stabbing it straight into a piece of ceramic tile. I couldn't help myself.

Very impressed.
There are a lot of 'super steels' regardless of Geometry that could not do that.

Thanks for sticking to real world use Cliff...er...um, bodog..............just kidding!!

This is the kind of info that helps us all, and it's what we need to stick to when we get into 'steel' conversations, otherwise it becomes just metal theory 101 with some added BS. Appreciate it man.