CPM SPY 27 Long Term Use

[Stas]

I have and use SPY27 knife just like any other. For me it is about the knife, not the steel. So not your “target audience” anyway.

[NCJohn62]

I bought the SPY27 Manix 2 lightweight shortly after it was released, it has been my primary summertime carry now for almost 2 years and gets plenty of use the other times of the year. I initially put a 17°edge on it @800 grit. Use includes everything from kitchen duty and cardboard breakdown through general cutting in the workshop.

Edge retention has been on par with other stainless steels in its category, I've never had the edge roll or chip even when using it on hard cutting surfaces. Corrosion resistance has been good as well. I find it easy to sharpen and strop back to a good working edge with only a few passes on 3 um diamond compound.

[WyoJon]

Seems to be common to hear its easy to sharpen. I like hearing that. Never liked s30v a whole lot for sharpening difficulties

[WyoJon]

I bought the SPY27 Manix 2 lightweight shortly after it was released, it has been my primary summertime carry now for almost 2 years and gets plenty of use the other times of the year. I initially put a 17°edge on it @800 grit. Use includes everything from kitchen duty and cardboard breakdown through general cutting in the workshop.

Edge retention has been on par with other stainless steels in its category, I've never had the edge roll or chip even when using it on hard cutting surfaces. Corrosion resistance has been good as well. I find it easy to sharpen and strop back to a good working edge with only a few passes on 3 um diamond compound.

Manix lw is tempting. I had one of the old sabre grounds s30v g10 manix back in college. That was a brick and a half. They dont even make them sabre ground for normal production now. That was back before the frn model. Ended up sellling it for $45 when I got tired of having 5 lbs of s30v and g10 anchoring my pants down. Liked the handle and blade shape a lot. Decided the native had almost as much blade and almost as much handle with a little more stream lined design so I ordered one in frn with spy27.

[ladybug93]

I bought the SPY27 Manix 2 lightweight shortly after it was released, it has been my primary summertime carry now for almost 2 years and gets plenty of use the other times of the year. I initially put a 17°edge on it @800 grit. Use includes everything from kitchen duty and cardboard breakdown through general cutting in the workshop.

Edge retention has been on par with other stainless steels in its category, I've never had the edge roll or chip even when using it on hard cutting surfaces. Corrosion resistance has been good as well. I find it easy to sharpen and strop back to a good working edge with only a few passes on 3 um diamond compound.

Manix lw is tempting. I had one of the old sabre grounds s30v g10 manix back in college. That was a brick and a half. They dont even make them sabre ground for normal production now. That was back before the frn model. Ended up sellling it for $45 when I got tired of having 5 lbs of s30v and g10 anchoring my pants down. Liked the handle and blade shape a lot. Decided the native had almost as much blade and almost as much handle with a little more stream lined design so I ordered one in frn with spy27.

the native is a little thicker behind the edge than the manix due to the blade not being as tall. i find the manix to be a slightly better slicer, but i agree the native is otherwise very similar to a smaller manix.

[WyoJon]

the native is a little thicker behind the edge than the manix due to the blade not being as tall. i find the manix to be a slightly better slicer, but i agree the native is otherwise very similar to a smaller manix.

I appreciate that feedback. That is great information. Not too woried about thickness behind the edge, ill just reprofile at 10 deg and convex it if it bothers me. I hated the old fat saber grinds of the manix back then. The newer ffg they all seem to have now is much better. I think i would enjoy a ffg manix very much, most likely the light weight since I am an frn junkie.

[Cl1ff]

My Spy27 lightweight Native 5 cuts pretty well and strops back nice. Even from the factory, I liked the edge “aggression” (I call it prickly) and stropping it actually seems to noticeably restore some of that aggression.

That said, I wouldn’t consider my experience with it “long term”.

[Deadboxhero]

Well I didn't address it to you directly it was more for just sharing the information from the time that was put in.

I think this is a good thread you made, it's nice to get people's thoughts and opinions about things.

When I first got started with a lot of this knife stuff I only believed in anecdotal testing.

As time went on it became problematic, say if I received a hundred different steels and had to figure out the differences between them I would need some sort of control to see differences simply because I would not have the time to anecdotally experience each one long-term, which also means each person's experience is limited to only a handful of steels and each steel may not be the maximum expression of that given steel.

Let's say you carry each steel for 2 years, Well chances are we are not going to live to be 200 years old.


Controlled testing is a consequence of our finite existence, our attention spans are also limited it's also nice to have clear distinctions between things for disseminating information to a larger audience.

It all plays together there's often a war in some circles of the knife community between controlled testing and anecdotal experiences when in reality they work together.

When we start getting into these super steels they stay cutting for so long we have to find a way to dull them more rapidly in a controlled way speed up what happens over time.

Controlled testing is a time machine, accelerate the time on the steel to make accurate predictions of future.

viewtopic.php?f=2&t=86859&hilit=SPY27+edge+performance

I read through that. I try not to revive old threads. Im not interested in machine tests on knife edges. Cutting rope is a cut test, but not an in depth study of daily usage

[WyoJon]

Well I didn't address it to you directly it was more for just sharing the information from the time that was put in.

I think this is a good thread you made, it's nice to get people's thoughts and opinions about things.

When I first got started with a lot of this knife stuff I only believed in anecdotal testing.

As time went on it became problematic, say if I received a hundred different steels and had to figure out the differences between them I would need some sort of control to see differences simply because I would not have the time to anecdotally experience each one long-term, which also means each person's experience is limited to only a handful of steels and each steel may not be the maximum expression of that given steel.

Let's say you carry each steel for 2 years, Well chances are we are not going to live to be 200 years old.


Controlled testing is a consequence of our finite existence, our attention spans are also limited it's also nice to have clear distinctions between things for disseminating information to a larger audience.

It all plays together there's often a war in some circles of the knife community between controlled testing and anecdotal experiences when in reality they work together.

When we start getting into these super steels they stay cutting for so long we have to find a way to dull them more rapidly in a controlled way speed up what happens over time.

Controlled testing is a time machine, accelerate the time on the steel to make accurate predictions of future.

viewtopic.php?f=2&t=86859&hilit=SPY27+edge+performance

I read through that. I try not to revive old threads. Im not interested in machine tests on knife edges. Cutting rope is a cut test, but not an in depth study of daily usage

The problem i had was 90% of what i was finding from people out there all went back to some tests Larrin did "too early". While Larrin did a good job of being consistant and using a quality machine, the tests are of little use in comparing blade steels because he used blank stock, and came up with his own heat treatment. The only way to be accurate is to use a knife, that spyderco has processed and done the heat treat on. The rest of it was people speculating based on reading the ingredients and not comprehending 1/10 of 1% of one ingredient in an alloy can make a big change.

[Deadboxhero]

The problem i had was 90% of what i was finding from people out there all went back to some tests Larrin did "too early". While Larrin did a good job of being consistant and using a quality machine, the tests are of little use in comparing blade steels because he used blank stock, and came up with his own heat treatment. The only way to be accurate is to use a knife, that spyderco has processed and done the heat treat on.

I disagree, I think there's some misunderstanding here of chemistry and heat treatment which is something I have a little bit of experience with.


We cannot create drastic increases of carbide volume or type which have a range that is fixed to the chemistry with heat treatment.

The different types of carbides and their volume was one of the most significant factors we saw when it came to differences between steels IF we are controlling for geometry, sharpness etc.
Real world will scatter the experiences drastically which may not be because they are actually seeing difference in steel but different but because there is just more scatter with anecdotes due to variables such as geometry, wear mode, how sharp or dull before testing/using etc, etc.

HRC was second to this which iIS one of big factors that can be controlled with heat treatment.

However the chemistry does play a role and how far you could push an HRC but you can certainly have a higher range of HRC can be controlled with heat treatment then you can control the ranges of carbides.

Again, it was the differences in the carbide type and volume as to why a steel with higher HRC (+65rc) technically did not cut as long as I steel with slightly lower HRC (~62-63rc)

No matter how hard we would get something like 1095 it only has 3% iron carbide (M3C 1000Hv) meaning in the microstructure these particles do not resist the wearing of the edge as well as SPY27 even if the 1095 is at extreme hardness 68rc for example. We would see the same effect on rope cutting. This is due to the small hard carbide particals in the steel matrix in the SPY27 at ~12% volume which happen to be significantly harder than iron carbide (M7C3 2000Hv, MC 2800Hv)

Again, for those reading along these particals are harder than the surrounding steel matrix increasing the slicing edge retention on CATRA yet also on rope if we control for geometry, sharpness etc.

The rest of it was people speculating based on reading the ingredients and not comprehending 1/10 of 1% of one ingredient in an alloy can make a big change.

Not necessarily,

For example adding a bit of tungsten 0.3% or even up to 1% W to vg10 does not equal increases in performance because of how things work.


Do you have a specific example we can work with here?

Let's frame this discussion into something more specific, such as a steel that you saw in the testing that you felt like could have been different?

Perhaps we start another thread?

I feel there's some good discussion to be had here but also this thread you made asking for anecdotes is also a fun topic.

[WyoJon]

The problem i had was 90% of what i was finding from people out there all went back to some tests Larrin did "too early". While Larrin did a good job of being consistant and using a quality machine, the tests are of little use in comparing blade steels because he used blank stock, and came up with his own heat treatment. The only way to be accurate is to use a knife, that spyderco has processed and done the heat treat on.

I disagree, I think there's some misunderstanding here of chemistry and heat treatment which is something I have a little bit of experience with.


We cannot create drastic increases of carbide volume or type which have a range that is fixed to the chemistry with heat treatment.

The different types of carbides and their volume was one of the most significant factors we saw when it came to differences between steels IF we are controlling for geometry, sharpness etc.
Real world will scatter the experiences drastically which may not be because they are actually seeing difference in steel but different but because there is just more scatter with anecdotes due to variables such as geometry, wear mode, how sharp or dull before testing/using etc, etc.

HRC was second to this which iIS one of big factors that can be controlled with heat treatment.

However the chemistry does play a role and how far you could push an HRC but you can certainly have a higher range of HRC can be controlled with heat treatment then you can control the ranges of carbides.

Again, it was the differences in the carbide type and volume as to why a steel with higher HRC (+65rc) technically did not cut as long as I steel with slightly lower HRC (~62-63rc)

No matter how hard we would get something like 1095 it only has 3% iron carbide (M3C 1000Hv) meaning in the microstructure these particles do not resist the wearing of the edge as well as SPY27 even if the 1095 is at extreme hardness 68rc for example. We would see the same effect on rope cutting. This is due to the small hard carbide particals in the steel matrix in the SPY27 at ~12% volume which happen to be significantly harder than iron carbide (M7C3 2000Hv, MC 2800Hv)

Again, for those reading along these particals are harder than the surrounding steel matrix increasing the slicing edge retention on CATRA yet also on rope if we control for geometry, sharpness etc.

The rest of it was people speculating based on reading the ingredients and not comprehending 1/10 of 1% of one ingredient in an alloy can make a big change.

Not necessarily,

For example adding a bit of tungsten 0.3% or even up to 1% W to vg10 does not equal increases in performance because of how things work.


Do you have a specific example we can work with here?

Let's frame this discussion into something more specific, such as a steel that you saw in the testing that you felt like could have been different?

Perhaps we start another thread?

I feel there's some good discussion to be had here but also this thread you made asking for anecdotes is also a fun topic.

I dont really have a lot to say about it other than speculating what adding different elements will do to a steel is as inaccurate as tests done on steel blanks assuming a finished blade that spyderco has heat treated will have the same properties.

Using a knife and sharpening it is the way to tell how it performs as a knife

[Bolster]

Control groups, and isolating the observed variable, are both extremely useful tools when making inferences. There’s a reason the scientific community attempts to avoid anecdotal evidence. With anecdotes, you’re buying a storyline. If you want a story, that’s cool — stories certainly have their place, and who doesn’t love a good story. If you want cold hard facts, on the other hand, then look for results from controlled experiments.

[sethwm]

Sal does say in the sharp maker video every 10 times of sharpening to go back to the 30 deg side and clean up the prinary bevel. Then fo back go sharpening on 40. So he seems to be on the same page as you there.

I missed that. I guess that applies to the golden stone too?

[WyoJon]

Sal does say in the sharp maker video every 10 times of sharpening to go back to the 30 deg side and clean up the prinary bevel. Then fo back go sharpening on 40. So he seems to be on the same page as you there.

I missed that. I guess that applies to the golden stone too?

Not sure, i havent watched a video for the golden stone. I like it, but it seems a bit redundant compared to sharp maker. A lot of the spyderco systems seem to be

[WyoJon]

Control groups, and isolating the observed variable, are both extremely useful tools when making inferences. There’s a reason the scientific community attempts to avoid anecdotal evidence. With anecdotes, you’re buying a storyline. If you want a story, that’s cool — stories certainly have their place, and who doesn’t love a good story. If you want cold hard facts, on the other hand, then look for results from controlled experiments.

Your right. And doing tests on steel blanks that arent processed by spyderco, and coming up with ideas of how a steel should perform in a knife based on looking at elements added and subtracted compared to another steel, are about as uncontrolled and far into the anecdote group as it gets. Thats why at the beginning of the thread I stated I wanted actual experience of using the knife, not those two groups that I outlined are not relevant.

[Bemo]

It seems WyoJon, that part of what you're trying to quantify is the difference between Spyderco's heat treat versus Larrin's, using the end user's anecdotal experience and reports. I think that's a tall order, but I commend the attempt.

And as Bolster is alluding to you're opening the door to all kinds of personal biases, confirmation bias only being one of those.

[JSumm]

Yeah, I can't offer any scientific data, just my limited experience. I have SPY27 in a Native 5 and a Manix LW. It seems the edge holds up well to hard interactions. I even used the Native to open up a door lock with no knob twisting at the edge. Did not see any noticable damage. I have scraped hard surfaces to get gunk and caulk off with the Native and again it held up at the edge very well. It is really a good fit for me me as a user steel. Both to how the edge holds up to abuse and how it sharpens back. To me the experience is similar to Cruwear in use. I like it a lot and I would definitely buy more. To note, I do not place high value on just wear resistance.

[WyoJon]

It seems WyoJon, that part of what you're trying to quantify is the difference between Spyderco's heat treat versus Larrin's, using the end user's anecdotal experience and reports. I think that's a tall order, but I commend the attempt.

And as Bolster is alluding to you're opening the door to all kinds of personal biases, confirmation bias only being one of those.

Larrin admitted he had no idea how spyderco treats the steel. Ive never worked with cpm steels. But i do know you take a chunk of 1095 head it to dull red and dunk it in water. It will be hard and very brittle. Snap right off. You then heat it to light blue and dunk it in water, it will be tempered, still have harness and now be flexible. Thats 3 entirely different properties, from one metal, with only heat treat varrying it. Metallurgy is much more advanced than some guy deciding some temperature he picks is a good point for a test.

If end user using and sharpening of steel knives was not consistant enough for any valid results, then spyderco would still be making knives in 440c and not use any other steels.

[WyoJon]

Yeah, I can't offer any scientific data, just my limited experience. I have SPY27 in a Native 5 and a Manix LW. It seems the edge holds up well to hard interactions. I even used the Native to open up a door lock with no knob twisting at the edge. Did not see any noticable damage. I have scraped hard surfaces to get gunk and caulk off with the Native and again it held up at the edge very well. It is really a good fit for me me as a user steel. Both to how the edge holds up to abuse and how it sharpens back. To me the experience is similar to Cruwear in use. I like it a lot and I would definitely buy more. To note, I do not place high value on just wear resistance.

I appreciate this feed back. Really solid information. Im sure from an anilysis of manufacturing efficiency, if spyderco designs their own steel it is to be a solid daily use steel fit for the average spyderco buyer.

[Deadboxhero]

And doing tests on steel blanks that arent processed by spyderco, and coming up with ideas of how a steel should perform in a knife based on looking at elements added and subtracted compared to another steel,

Articulate what the speculation is it is difficult to have a discussion about what you think is going on versus what's actually going on.

Are you saying that how Larrin had heat treated something company A would get a drastically different result based on what? And what would the difference be?


Contextualize your thoughts.

looking at elements added and subtracted compared to another steel, are about as uncontrolled and far into the anecdote group as it gets. Thats why at the beginning of the thread I stated I wanted actual experience of using the knife, not those two groups that I outlined are not relevant.

The CATRA study wasn't about adding and subtracting steel chemistry wt% to see differences. Thats not how we understand how things work.

I disagree, I'm interpreting what you're saying (correct me if im wrong) is that the CATRA test was just as uncontrolled as getting anecdotal accounts from the public?

Geometry is one of the most powerful variables.

Those blades were all at the same geometry and sharpness closer than anything we have gotten in any previous edge testing looking at such a high volume of different steels.

Like I said before it's important to have both control testing and anecdotal accounts.

I'm not trying marginalize anecdotal accounts.

However we would be at a huge loss to the community if we try to marginalize controlled testing.