‘Carbides in Maxamet’ article in the Scienceofsharp

[The Mastiff]

There is an image of carbide pullout in this article:

Yes sir, that is an article I kept on my PC and refer back to now and again. The carbide tear out issue is not new and fairly well understood to an extent but I'm not going to get behind the common knowledge that all high carbide steel " loses high sharpness quickly then keeps low/medium sharpness forever" because of the carbides tearing out " .

There is often a grain of truth in such things but I just don't feel good about setting hard and fast rules about classes of steel based on carbides alone. As you have wrote about things like RA are going to change performance at the edge. Heat treat and tempering temps and cryo treatment change the performance and structure (?) of the steel and two edges can work completely differently even when the rc values are the same. Naturally powder process steels have changed our hobby greatly as well.

The more I learn about this subject the less I want to rely on common knowledge on forums and have found a few well known facts to be lacking. Still, as stated I don't want to overlook the truth just because something is a popular opinion. :)

[Cambertree]

Thanks for the great input and discussion all.

A bit of background to the Scienceofsharp blog, for those who are not familiar with it.

Most of the images and general focus of the blog is on straight razor sharpening - so thin acute edge angles (usually around 16-17 degrees inclusive), in ‘simple’ carbon steels. The edge finish is usually aimed at achieving a comfortable, clean shave.

So there are clearly some techniques, and conclusions which may not carry over to the full array of modern steel types which are offered by Spyderco in folding and fixed blade knives.

I think there are a couple of SEM photos of H1 and ZDP189 edges on Spyderco knives in some previous posts on burr removal, IIRC.

The breadth of knowledge and experience of different steels and cutting applications in this forum is possibly a fair bit wider than the purist straight razor afi crew.

Nevertheless, I find it fascinating to actually be able to see edges which have been abraded with different grits and techniques.

Pelagic, there’s actually some interesting posts on the blog, where Simpson demonstrates how a straight 325 grit DMT plate can achieve a smooth shaving finish. I’m guessing the low corrosion resistance might be an issue, but have you tried Maxamet out on the boat? I’d guess it’d be a fierce cutter with a coarse diamond finish on those synthetic materials you deal with.

I currently run my Maxamet Para 3 like this: I’ve thinned out the edge with a backbevel on the Atomas and Venevs at around 12 dps, but stopped just short of apexing. Then I set up a crude 15dps wood jig and apexed with the 400 and 800 FEPA-F Venev OCB bonded diamond stones. Lastly I crisped up the edge with a really light M and F 20dps microbevel on the Sharpmaker rods.

I was trying to get a reasonably thin edge for decent performance, while still being cautious due to the large carbide volume of Maxamet.

It seems to work pretty well, although I haven’t done anything more than anecdotal EDC carry and use.

I must admit, I’m kind of fascinated by those alumina abraded edges, and I’m tempted to experiment with them, next time I need to sharpen my Para 3.

[emanuel]

Larger carbides are more likely to fracture or separate from the matrix from applied stress. The article provides some fun images for sure. I wouldn't say that it shows that carbides do not "tear out" however. The images are showing the carbides that didn't fall out, obviously. He is more demonstrating that many carbides are still there. He seems to be arguing against those that say that all of them easily fall out I guess. I didn't know that is a popular opinion.

My interpretation of given data is different than the author/Todd of linked page/article. Obviously conclusion would also different.

Hey guys. Shouldn't the white spots be just a different type of carbides compared to the darker gray ones? It seems like in a later image you can see two of them cracked instead of just deformed. I also thought austenite will only be differentiated from martensite after etching the surface of the metal. Or does that only apply to optical microscopes, not electron ones?

P.S. : I'm also curious now if the Spyderco fine ceramic stones have the same carbide-exposing effect on high carbide steels as the shapton/japanese stones.

[Larrin]

Hey guys. Shouldn't the white spots be just a different type of carbides compared to the darker gray ones? It seems like in a later image you can see two of them cracked instead of just deformed. I also thought austenite will only be differentiated from martensite after etching the surface of the metal. Or does that only apply to optical microscopes, not electron ones?

I don't know why bluntcut is interpreting carbides as retained austenite.

[Larrin]

There is an image of carbide pullout in this article:

Yes sir, that is an article I kept on my PC and refer back to now and again. The carbide tear out issue is not new and fairly well understood to an extent but I'm not going to get behind the common knowledge that all high carbide steel " loses high sharpness quickly then keeps low/medium sharpness forever" because of the carbides tearing out " .

There is often a grain of truth in such things but I just don't feel good about setting hard and fast rules about classes of steel based on carbides alone. As you have wrote about things like RA are going to change performance at the edge. Heat treat and tempering temps and cryo treatment change the performance and structure (?) of the steel and two edges can work completely differently even when the rc values are the same. Naturally powder process steels have changed our hobby greatly as well.

The more I learn about this subject the less I want to rely on common knowledge on forums and have found a few well known facts to be lacking. Still, as stated I don't want to overlook the truth just because something is a popular opinion. :)

I agree I don't think carbides typically tear out during slicing. In the images of the edges after CATRA testing the edges looked very smooth without evidence of carbide pullout. Sharpening seems to be a bit different case. With stress/impact the situation is also likely to be a bit different.

[Ankerson]

There is an image of carbide pullout in this article:

The more I learn about this subject the less I want to rely on common knowledge on forums and have found a few well known facts to be lacking. Still, as stated I don't want to overlook the truth just because something is a popular opinion. :)

Joe,

Most of the so called well known facts are complete BS started by shills... The same ones that say that you can't sharpen X steels with SIC... And you need diamonds...

Repeated enough times they somehow become facts even though they are wrong. Kinda like the Earth is Flat...

Not going to get into it here, but it does matter what you sharpen the knife with. Diamonds tear and rip up (NOT a good thing) the steel a lot more than other sharpening media and could cause a lot of the so called carbide tear out.. But then you won't read that due to the shills promoting diamond stones etc.

I have sharpened just about every steel from simple carbon steels up to and including MAXAMET with SIC stones with ZERO issues.


Also Ceramic like the Shapton Glass are good and or the Sharpmaker. Although I believe I get a better edge with my SIC stones I use than with the Shapton Glass stones. The SIC stones also cut faster at the same Micron rating, the ones I use do anyway.



Jim

[Deadboxhero]

There is an image of carbide pullout in this article:

The more I learn about this subject the less I want to rely on common knowledge on forums and have found a few well known facts to be lacking. Still, as stated I don't want to overlook the truth just because something is a popular opinion. :)

Joe,

Most of the so called well known facts are complete BS started by shills... The same ones that say that you can't sharpen X steels with SIC... And you need diamonds...

Repeated enough times they somehow become facts even though they are wrong. Kinda like the Earth is Flat...

Not going to get into it here, but it does matter what you sharpen the knife with. Diamonds tear and rip up (NOT a good thing) the steel a lot more than other sharpening media and could cause a lot of the so called carbide tear out.. But then you won't read that due to the shills promoting diamond stones etc.

I have sharpened just about every steel from simple carbon steels up to and including MAXAMET with SIC stones with ZERO issues.


Also Ceramic like the Shapton Glass are good and or the Sharpmaker. Although I believe I get a better edge with my SIC stones I use than with the Shapton Glass stones. The SIC stones also cut faster at the same Micron rating, the ones I use do anyway.



Jim

Nah, a low grit, coated diamond stone will make an egde that cuts longer in CATRA testing than SiC at the same grit.

Deeper cut, more microserrations.

Bonded stones cut faster than SiC with less glazing at the edge.

The effect is noticed more when the steel is harder.

[Ankerson]

There is an image of carbide pullout in this article:

The more I learn about this subject the less I want to rely on common knowledge on forums and have found a few well known facts to be lacking. Still, as stated I don't want to overlook the truth just because something is a popular opinion. :)

Joe,

Most of the so called well known facts are complete BS started by shills... The same ones that say that you can't sharpen X steels with SIC... And you need diamonds...

Repeated enough times they somehow become facts even though they are wrong. Kinda like the Earth is Flat...

Not going to get into it here, but it does matter what you sharpen the knife with. Diamonds tear and rip up (NOT a good thing) the steel a lot more than other sharpening media and could cause a lot of the so called carbide tear out.. But then you won't read that due to the shills promoting diamond stones etc.

I have sharpened just about every steel from simple carbon steels up to and including MAXAMET with SIC stones with ZERO issues.


Also Ceramic like the Shapton Glass are good and or the Sharpmaker. Although I believe I get a better edge with my SIC stones I use than with the Shapton Glass stones. The SIC stones also cut faster at the same Micron rating, the ones I use do anyway.



Jim

Nah, a low grit, coated diamond stone will make an egde that cuts longer in CATRA testing than SiC at the same grit.

Deeper cut, more microserrations.

Bonded stones cut faster than SiC with less glazing at the edge.

The effect is noticed more when the steel is harder.

Not in my experience they don't....

Diamonds do cut faster though, that is well known because they rip and tear up the steel much more. Faster for grinding, but not so much for sharpening..

I have had this talk with people who are not trying to sell anyone anything more than a few times over the years...

In other words I am not changing what I use.

[Deadboxhero]

Keep an open mind, there are a lot of new stones you have not tried that don't have the same effect as the coated stuff.


Regardless a coated diamond stone edge will win in CATRA testing over the SIC edge, we can send out edges to CATRA and make a bet if you like, the loser pays the bill for the testing.

$75 per test, $150 total.

Let me know.
A little competition is fun.

The more I learn about this subject the less I want to rely on common knowledge on forums and have found a few well known facts to be lacking. Still, as stated I don't want to overlook the truth just because something is a popular opinion. :)

Joe,

Most of the so called well known facts are complete BS started by shills... The same ones that say that you can't sharpen X steels with SIC... And you need diamonds...

Repeated enough times they somehow become facts even though they are wrong. Kinda like the Earth is Flat...

Not going to get into it here, but it does matter what you sharpen the knife with. Diamonds tear and rip up (NOT a good thing) the steel a lot more than other sharpening media and could cause a lot of the so called carbide tear out.. But then you won't read that due to the shills promoting diamond stones etc.

I have sharpened just about every steel from simple carbon steels up to and including MAXAMET with SIC stones with ZERO issues.


Also Ceramic like the Shapton Glass are good and or the Sharpmaker. Although I believe I get a better edge with my SIC stones I use than with the Shapton Glass stones. The SIC stones also cut faster at the same Micron rating, the ones I use do anyway.



Jim

Nah, a low grit, coated diamond stone will make an egde that cuts longer in CATRA testing than SiC at the same grit.

Deeper cut, more microserrations.

Bonded stones cut faster than SiC with less glazing at the edge.

The effect is noticed more when the steel is harder.

Not in my experience they don't....

Diamonds do cut faster though, that is well known because they rip and tear up the steel much more. Faster for grinding, but not so much for sharpening..

[Ankerson]

Keep an open mind, there are a lot of new stones you have not tried that don't have the same effect as the coated stuff.


Regardless a coated diamond stone edge will win in CATRA testing over the SIC edge, we can send out edges to CATRA and make a bet if you like, the loser pays the bill for the testing.

$75 per test, $150 total.

Let me know.
A little competition is fun.

Joe,

Most of the so called well known facts are complete BS started by shills... The same ones that say that you can't sharpen X steels with SIC... And you need diamonds...

Repeated enough times they somehow become facts even though they are wrong. Kinda like the Earth is Flat...

Not going to get into it here, but it does matter what you sharpen the knife with. Diamonds tear and rip up (NOT a good thing) the steel a lot more than other sharpening media and could cause a lot of the so called carbide tear out.. But then you won't read that due to the shills promoting diamond stones etc.

I have sharpened just about every steel from simple carbon steels up to and including MAXAMET with SIC stones with ZERO issues.


Also Ceramic like the Shapton Glass are good and or the Sharpmaker. Although I believe I get a better edge with my SIC stones I use than with the Shapton Glass stones. The SIC stones also cut faster at the same Micron rating, the ones I use do anyway.



Jim

Nah, a low grit, coated diamond stone will make an egde that cuts longer in CATRA testing than SiC at the same grit.

Deeper cut, more microserrations.

Bonded stones cut faster than SiC with less glazing at the edge.

The effect is noticed more when the steel is harder.

Not in my experience they don't....

Diamonds do cut faster though, that is well known because they rip and tear up the steel much more. Faster for grinding, but not so much for sharpening..

Already did my testing....

And a lot of it over the years.

Like I said I am not changing...

[Deadboxhero]

Too bad

Keep an open mind, there are a lot of new stones you have not tried that don't have the same effect as the coated stuff.


Regardless a coated diamond stone edge will win in CATRA testing over the SIC edge, we can send out edges to CATRA and make a bet if you like, the loser pays the bill for the testing.

$75 per test, $150 total.

Let me know.
A little competition is fun.

Nah, a low grit, coated diamond stone will make an egde that cuts longer in CATRA testing than SiC at the same grit.

Deeper cut, more microserrations.

Bonded stones cut faster than SiC with less glazing at the edge.

The effect is noticed more when the steel is harder.

Not in my experience they don't....

Diamonds do cut faster though, that is well known because they rip and tear up the steel much more. Faster for grinding, but not so much for sharpening..

Already did my testing....

And a lot of it over the years.

Like I said I am not changing...

[The Mastiff]

Back when S30V was new and supposed to be chippy on the edge I had one S30V knife that did micro chip. There were places where it looked like the carbides were tearing out. I wanted to rule out sharpening issues being the cause and found out in my case sharpening was exactly the cause. I had been using very low grit diamond DMT stones and pressing too hard. I went up to 200 grit to begin with and lightened the pressure applied and then continued up 400, then 600, 800 etc. and found no micro chipping/brittle edges remained. I had been using 80 grit then going up to 800 and a thousand to finish while having trouble. I've never had problems with any well heat treated steel since then. In my case I became satisfied there was nothing inherently wrong with S30v but I also became aware how easily edges can be damaged by incorrect sharpening techniques. Diamonds magnified the results of my mistakes. When done correctly they are real helpful with high wear steels. Is that too obvious of a statement? :)

Joe

[Ankerson]

Back when S30V was new and supposed to be chippy on the edge I had one S30V knife that did micro chip. There were places where it looked like the carbides were tearing out. I wanted to rule out sharpening issues being the cause and found out in my case sharpening was exactly the cause. I had been using very low grit diamond DMT stones and pressing too hard. I went up to 200 grit to begin with and lightened the pressure applied and then continued up 400, then 600, 800 etc. and found no micro chipping/brittle edges remained. I had been using 80 grit then going up to 800 and a thousand to finish while having trouble. I've never had problems with any well heat treated steel since then. In my case I became satisfied there was nothing inherently wrong with S30v but I also became aware how easily edges can be damaged by incorrect sharpening techniques. Diamonds magnified the results of my mistakes. When done correctly they are real helpful with high wear steels. Is that too obvious of a statement? :)

Joe

Joe,

Sharpening techniques can be and is a lot of the problems that people seemed/seem to be having.

A lot of the issues with some steels could be linked to sharpening over the years.

But the steels got blamed and still do today.

People do seem to overthink and overcomplicate sharpening quite a bit though making things leaps and bounds harder than they really need to be.

Jim

[The Mastiff]

People do seem to overthink and overcomplicate sharpening quite a bit though making things leaps and bounds harder than they really need to be.

Man, that is a lot of truth Jim! Not just sharpening either. :)

[Ankerson]

People do seem to overthink and overcomplicate sharpening quite a bit though making things leaps and bounds harder than they really need to be.

Man, that is a lot of truth Jim! Not just sharpening either. :)

Joe,

Yeah, you got that right. LOL

Sometimes people tend to think too much.

Thinking themselves right into issues.

The old saying is:

Think long, think wrong.

The K.I.S.S. method is usually best with just about anything..

Jim

[blues]

Jim, I think a lot of folks owe you a debt for showing just what is possible with simple SiC (Mold Master) hones in 320 and 400 grit. (And the skill to employ them properly.)

Certainly there are grades and shades of difference between various levels of sharpening and polish, but the results you achieved while keeping it simple speak for themselves, imho.

[Ankerson]

Jim, I think a lot of folks owe you a debt for showing just what is possible with simple SiC (Mold Master) hones in 320 and 400 grit. (And the skill to employ them properly.)

Certainly there are grades and shades of difference between various levels of sharpening and polish, but the results you achieved while keeping it simple speak for themselves, imho.

Thanks,

Good stones and keeping things simple can be a good thing. :)

Been using SIC for about 45 years as my main sharpening media.

Something to be said about 400 grit and SIC, has been the standard for a very long time and for good reason. :)

I do use ceramics for touch ups and have used other stones over the years off and on, but I kept going back to SIC.

The Mold Masters are the best SIC stones I have ever used. Very little filler so not much slurry at all as in almost zero when sharpening.

Jim

[vivi]

Keep an open mind, there are a lot of new stones you have not tried that don't have the same effect as the coated stuff.


Regardless a coated diamond stone edge will win in CATRA testing over the SIC edge, we can send out edges to CATRA and make a bet if you like, the loser pays the bill for the testing.

$75 per test, $150 total.

Let me know.
A little competition is fun.

Joe,

Most of the so called well known facts are complete BS started by shills... The same ones that say that you can't sharpen X steels with SIC... And you need diamonds...

Repeated enough times they somehow become facts even though they are wrong. Kinda like the Earth is Flat...

Not going to get into it here, but it does matter what you sharpen the knife with. Diamonds tear and rip up (NOT a good thing) the steel a lot more than other sharpening media and could cause a lot of the so called carbide tear out.. But then you won't read that due to the shills promoting diamond stones etc.

I have sharpened just about every steel from simple carbon steels up to and including MAXAMET with SIC stones with ZERO issues.


Also Ceramic like the Shapton Glass are good and or the Sharpmaker. Although I believe I get a better edge with my SIC stones I use than with the Shapton Glass stones. The SIC stones also cut faster at the same Micron rating, the ones I use do anyway.



Jim

Nah, a low grit, coated diamond stone will make an egde that cuts longer in CATRA testing than SiC at the same grit.

Deeper cut, more microserrations.

Bonded stones cut faster than SiC with less glazing at the edge.

The effect is noticed more when the steel is harder.

Not in my experience they don't....

Diamonds do cut faster though, that is well known because they rip and tear up the steel much more. Faster for grinding, but not so much for sharpening..

I have to say, even going off of old school plated diamonds, what deadboxhero is saying is 100% correct.

I haven't run into a steel SiC stones couldn't make sharper, but I also haven't run into a steel where SiC does a superior job to diamonds every time.

Jim, what diamond stones did you try? How long ago?

[Deadboxhero]

I've talked to Jim on the phone, I ordered a Congress moldmaster stone.

I have a square piece of CPM 10v

I'll grind it both sides, sharpen one side with an atoma 400grit, the other side with a 400grit Moldmaster SiC.

Then I'll send to Catra

[blues]

Cool, Shawn. Now don't cheat. LOL!