CPM SPY 27 Long Term Use

[WyoJon]

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 he 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.

Those are two different groups, as far as Larrin tests, he said he was using spy27 stock that was not heat treated and not formed into knife blades. That makes the results irrelevant to blades processed by spyderco. You seem to not understand the drastic changes in properties of steel between the cold rolled state, and being hardened with heat, and then tempered with heat. Just a few degrees for each of those steps can make a big difference in the characteristics of a blade. As well as the mixture that is being quenched into. That is why I am saying taking steel blanks and not understanding spydercos heat treating and forging process would give results that are inaccurate.

As for anecdote, someone obererving their experiences of using a knife, how it dulls, and how it responds to different sharpening systems is not an anecdote. An anecdote would be "30 years ago my uncle had a friend who had a blade with cpm spy27 and he could cut doors off cars with that knife, and it was always shaving sharp"

See the difference?

[JSumm]

I really think Larrin's testing has brought a lot of clarity to all the steels and what their possibilities are and how they are specialized. It eliminates as many variables as possible and gives us the clearest picture we have to date.

Now, the cool thing is, we get to go and enjoy these steels. I personally like good wear resistance and great edge stability with a steel that is easier to sharpen. So I typically like to stay under the 4% Vanadium threshold based on my anecdotal experience. Seems like those sharpen a bit easier for someone like me without great skill. The edges hold up well on certain steels in that category based on who produced it, and I find I enjoy those steels more. But, I wouldn't know where to start without Larrin's testing because the experience you hear often is scattered. It is like product reviews, you have to throw out the outliers and see where the common ground is. Larrin's testing makes that a little easier for me now.

[WyoJon]

I really think Larrin's testing has brought a lot of clarity to all the steels and what their possibilities are and how they are specialized. It eliminates as many variables as possible and gives us the clearest picture we have to date.

Now, the cool thing is, we get to go and enjoy these steels. I personally like good wear resistance and great edge stability with a steel that is easier to sharpen. So I typically like to stay under the 4% Vanadium threshold based on my anecdotal experience. Seems like those sharpen a bit easier for someone like me without great skill. The edges hold up well on certain steels in that category based on who produced it, and I find I enjoy those steels more. But, I wouldn't know where to start without Larrin's testing because the experience you hear often is scattered. It is like product reviews, you have to throw out the outliers and see where the common ground is. Larrin's testing makes that a little easier for me now.

I like that statement. But your personal results would not be an anecdote. I too hate sharpening high vanadium steels. Thats not anyone lacking skill, they are made to resist wear. That is why railroad track is made from steel high in vanadium.

[JSumm]

True. Maybe better said for me is stay in your lane. I'm not slicing paper towels in an S like our man Shawn with 15V. I practice a lot, so maybe one day, but not today. So SPY27 checks a lot of boxes for me. I think it is a great user steal and Sal and Co. knew what they were doing when they designed it. An updated PM VG-10 with better edge stability. That is how I would look at it. Not sure if that is what they were going for, but I think they did a great job. At least for someone like me. I want more.

So... When can we get a Manix and Caly 3.5 both with some blue G10 in SPY27???

[vandelay]

I really think Larrin's testing has brought a lot of clarity to all the steels and what their possibilities are and how they are specialized. It eliminates as many variables as possible and gives us the clearest picture we have to date.

Now, the cool thing is, we get to go and enjoy these steels. I personally like good wear resistance and great edge stability with a steel that is easier to sharpen. So I typically like to stay under the 4% Vanadium threshold based on my anecdotal experience. Seems like those sharpen a bit easier for someone like me without great skill. The edges hold up well on certain steels in that category based on who produced it, and I find I enjoy those steels more. But, I wouldn't know where to start without Larrin's testing because the experience you hear often is scattered. It is like product reviews, you have to throw out the outliers and see where the common ground is. Larrin's testing makes that a little easier for me now.

I like that statement. But your personal results would not be an anecdote. I too hate sharpening high vanadium steels. Thats not anyone lacking skill, they are made to resist wear. That is why railroad track is made from steel high in vanadium.

I sharpen on DMT plates and I find it easier to get high vanadium steel like k390 sharp than stainless like S30V or XHP. I suspect there's some sort of microchipping going on. It's possible that something like a vitrified diamond stone wouldn't have the same microchipping issue. There are a lot of variables that go into sharpening performance beyond wear resistance.

[Deadboxhero]

Those are two different groups, as far as Larrin tests, he said he was using spy27 stock that was not heat treated and not formed into knife blades. That makes the results irrelevant to blades processed by spyderco.

Are you implying its not normally supplied that way?

You seem to not understand the drastic changes in properties of steel between the cold rolled state, and being hardened with heat, and then tempered with heat.

Well, explain it to me? How does it work?

Perhaps you can give a quick, simple explanation of your understanding of it?

Just a few degrees for each of those steps can make a big difference in the characteristics of a blade.

Which step is the most significant effect and how?

As well as the mixture that is being quenched into.

How are they quenched? Mixture? Quenchant mixture?

That is why I am saying taking steel blanks

What is a steel blank? Just "annealed" steel?

and not understanding spydercos heat treating and forging process would give results that are inaccurate.

Forged? The blades are forged out? Drop forged? Hammer forged?

As for anecdote, someone obererving their experiences of using a knife, how it dulls, and how it responds to different sharpening systems is not an anecdote. An anecdote would be "30 years ago my uncle had a friend who had a blade with cpm spy27 and he could cut doors off cars with that knife, and it was always shaving sharp"

See the difference?

I agree to disagree, those are both examples of anecdotal evidence.


"Anecdotal evidence is usually based on individual experiences or observations"

-Les Irwig

[Deadboxhero]

That is why railroad track is made from steel high in vanadium.

What steel do they use?

[WyoJon]

True. Maybe better said for me is stay in your lane. I'm not slicing paper towels in an S like our man Shawn with 15V. I practice a lot, so maybe one day, but not today. So SPY27 checks a lot of boxes for me. I think it is a great user steal and Sal and Co. knew what they were doing when they designed it. An updated PM VG-10 with better edge stability. That is how I would look at it. Not sure if that is what they were going for, but I think they did a great job. At least for someone like me. I want more.

So... When can we get a Manix and Caly 3.5 both with some blue G10 in SPY27???

I agree. I use thin rolling papers to test knife sharpness. The ones you can read through. If it slices it easily in a controllable manner with no support of the paper, its sharp enough. I also finish everything on the ultra fine sharp maker stone. Even edges i free hand on bench stones not related to spyderco products.

[Bemo]

WYO, just to check foundational knowledge, not meaning to questions anything, you do know Larrin heat treats all those steel tabs right? And you do know that he and Shawn know their way around heat treating and sharpening right? And when Larrin does the Catra testing many times Shawn did the sharpening of those pieces (he was a professional knife sharpener prior to being a custom knife maker). I assume Larrin does a pretty bog standard heat treat based in part on the manufacturers recommendations; so no it won't be exactly what Spyderco does but I'll bet it's not too far off and the results Larrin gets can at least be extrapolated to a certain extent (confidence interval of 10%) to what Spyderco does. Exact? No. SWAG, definitely.

[Bolster]

Interesting conversation, thanks WyoJon.

If the hypothesis is: there’s a noticeable difference in the performance of HTs among very experienced metallurgists & manufacturers who are at the top of their games (Doc Thomas, Spyderco), really the only way to test that, is to get samples from both sources that are as similar as possible, and test. That’s a problem, since Larrin doesn’t manufacture blades to be tested. (There is a drawback with Dr. Thomas’ reports; nobody is replicating his tests--that I know of, at least. Not Dr. Thomas’ fault—as a scientist I’m sure he’d turn over his materials for replication, but I’m unaware of others with his equipement, expertise, and interest, who are willing to do free, expensive, time-consuming work replicating his results). However, anectodal evidence from users would provide weak evidence as substitute; anecdotes are a coarse measure, affected by many uncontrolled variables.

As for anecdote, someone obererving their experiences of using a knife, how it dulls, and how it responds to different sharpening systems is not an anecdote.

Actually, that is a nearly perfect example of an anecdote. In scientific circles, an anecdote is defined as an informal account, experienced by an individual, based on n=1. The completeness and accuracy of anecdotes is unknown. Granted, years ago, that’s what knife knuts had to work with, and as the famous saying goes, “the plural of anecdotes is not data.” I feel lucky to live in a time when scientific approaches are revolutionizing what we know, even about formerly “fringe” topics.

Oddly, this conversation is verging on an epistemological discussion…from what source do we derive truth? Who knew we could get so deep on the Spyderco forum~

[Bemo]

Really an awesome conversation.

[WyoJon]

Really an awesome conversation.

It is. Were getting some solid data on how this steel is performing for people. Ive noticed a few good reviews of it added to the sharpeners
Steels thread in the last day

Its threads like this that will help this steel sell. I was on the fence about it since there are almost no reviews and no cut test videos or sharpening information available online about this steel. Was afraid id end up with another one of those steels for the people who cant bring themselves to sharpen a knife and send it away twice a year.

[JSumm]

You can check out Outpost76 on YouTube. Gerald has done some cut test with it if you are interested.

[wrdwrght]

Interesting conversation, thanks WyoJon.

If the hypothesis is: there’s a noticeable difference in the performance of HTs among very experienced metallurgists & manufacturers who are at the top of their games (Doc Thomas, Spyderco), really the only way to test that, is to get samples from both sources that are as similar as possible, and test. That’s a problem, since Larrin doesn’t manufacture blades to be tested. (There is a drawback with Dr. Thomas’ reports; nobody is replicating his tests--that I know of, at least. Not Dr. Thomas’ fault—as a scientist I’m sure he’d turn over his materials for replication, but I’m unaware of others with his equipement, expertise, and interest, who are willing to do free, expensive, time-consuming work replicating his results). However, anectodal evidence from users would provide weak evidence as substitute; anecdotes are a coarse measure, affected by many uncontrolled variables.

As for anecdote, someone obererving their experiences of using a knife, how it dulls, and how it responds to different sharpening systems is not an anecdote.

Actually, that is a nearly perfect example of an anecdote. In scientific circles, an anecdote is defined as an informal account, experienced by an individual, based on n=1. The completeness and accuracy of anecdotes is unknown. Granted, years ago, that’s what knife knuts had to work with, and as the famous saying goes, “the plural of anecdotes is not data.” I feel lucky to live in a time when scientific approaches are revolutionizing what we know, even about formerly “fringe” topics.

Oddly, this conversation is verging on an epistemological discussion…from what source do we derive truth? Who knew we could get so deep on the Spyderco forum~

And, you, Bolster, made this conversation even more interesting. Excellent, that is, wonderfully aware, comments.

[Deadboxhero]

True. Maybe better said for me is stay in your lane. I'm not slicing paper towels in an S like our man Shawn with 15V. I practice a lot, so maybe one day, but not today. So SPY27 checks a lot of boxes for me. I think it is a great user steal and Sal and Co. knew what they were doing when they designed it. An updated PM VG-10 with better edge stability. That is how I would look at it. Not sure if that is what they were going for, but I think they did a great job. At least for someone like me. I want more.

So... When can we get a Manix and Caly 3.5 both with some blue G10 in SPY27???

I agree. I use thin rolling papers to test knife sharpness. The ones you can read through. If it slices it easily in a controllable manner with no support of the paper, its sharp enough. I also finish everything on the ultra fine sharp maker stone. Even edges i free hand on bench stones not related to spyderco products.

You didn't answer my questions

[wrdwrght]

An updated PM VG-10 with better edge stability. That is how I would look at it.

Now I’m interested. I must have missed the memo.

[GarageBoy]

That is why railroad track is made from steel high in vanadium.

What steel do they use?

From the casual googling I've done, it seems to be 1084 which isn't high vanadium?

https://www.fedsteel.com/insights/steel ... ay-tracks/

This mentions use of higher alloy steel rail in specialty use

[JSumm]

An updated PM VG-10 with better edge stability. That is how I would look at it.

Now I’m interested. I must have missed the memo.

Sal talked a little about it on here. There is also a good write up in the paperwork that comes with the SPY27 models. I can't get to it now, but I'll try to scan it later to upload here.

[wrdwrght]

An updated PM VG-10 with better edge stability. That is how I would look at it.

Now I’m interested. I must have missed the memo.

Sal talked a little about it on here. There is also a good write up in the paperwork that comes with the SPY27 models. I can't get to it now, but I'll try to scan it later to upload here.

Thanks, Jeff.

[WyoJon]

That is why railroad track is made from steel high in vanadium.

What steel do they use?

From the casual googling I've done, it seems to be 1084 which isn't high vanadium?

https://www.fedsteel.com/insights/steel ... ay-tracks/

This mentions use of higher alloy steel rail in specialty use

The problem your going to have is that the global corporation that owns the track work foundries in america and much of the world is tight lipped about their process. Those who know are not allowed to talk about it.

It is well known rail track of modern production is high in vanadium