Where does SPY27 Steel sits among the current Steel lines?

[SpyderFlicker]

As the title says, Where does SPY27 Steel sit among the current Steel lines like S30V, BD1N, 20CV ?

[Cambertree]

Larrin’s articles are probably your best port of call, if you haven’t read them yet:

https://knifesteelnerds.com/2020/01/15/ ... -analysis/

https://knifesteelnerds.com/2020/03/02/ ... -and-more/

[JuPaul]

Larrin's articles are definitely the best resource, but you can also see this thread for user first impressions:
viewtopic.php?t=86824&start=60

In my subjective experience, I feel like in has edge retention slightly less than s30v, but was easier and more fun to sharpen. Others felt the edge retention was even better than s30v.

[steelcity16]

Sounds like an improved S35VN. I am interested to try it. I hope we will see it in the Seki stuff soon as more US steels make their way into those models.

[p_atrick]

I hope we will see it in the Seki stuff soon as more US steels make their way into those models.

This. It's been a while since I got myself a new knife. I've been thinking I should treat myself to something nice. But what I really want is SPY-27 in the Seki line. First, I'm curious about the steel, and it seems right up my alley. Second, I've grown more and more attached to the Seki knives. I went from an Endura to nicer and more fidget-friendly knives. After getting the P4LW, I realize that the Seki line has all I need. You get a wife variety of shapes and sizes. You also get tool steels, stainless steels, and sprint runs. What more could you want? SPY-27 is the only thing missing.

[SubMicron]

It's important that "wear resistance" doesn't get confused with "edge retention"

It's a tricky subject and I have no problem admitting that I dont have a full comprehension of the subject matter. Anyone is welcome to correct me where I'm wrong, or otherwise fill in any holes.

Wear resistance, as measured through CATRA tests, involves a machine cutting sillica impregnated cardstock... kinda almost similar to sand and grit filled dirty cardboard. The CATRA test brings the knife edge to a point of extreme dullness... way past where most of us would just sharpen our knives.

Based on CATRA tests, one should expect SPY-27 to stack up slightly below S30V when cutting abrasive materials, especially if you're completely dulling the edge before sharpening.

What CATRA does not measure is the front end edge retention, especially through non abrasive materials, such as clean cardboard, cloth, tape, plastic, etc.

Im talking about how much can it cut before it stops easily cutting.... not before it's dull.

I've run multiple tests on SPY-27 in a controlled test in brand new clean cardboard, taping off a 1" section to test until it no longer reliably slices paper.

Both the Benchmade Bugout S30V and Spyderco Lil Native S30V give me a test result of about 150 feet, every time.

Meanwhile SPY-27 consistently does about 300 feet in the same test.

While it's wear resistance is slightly less than S30V, when the edge is maintained like most of us do, and non abrasive materials are cut, like most of us cut, SPY-27 will have noticeably superior edge retention.

What you're cutting matters most... for example S30V, SPY-27, and Maxamet all have exactly the same edge retention when tested against a brick. Each will cut precisely the same amount of bricks, obviously zero.

[spyderg]

In my use I’m finding it similar to ctsxhp in terms of toughness, edge retention and sharpening. Both remain spotless from my fairly corrosive sweat.

[sal]

Thanx SubMicron,

I have also found that SPY27 for some reason, seems to be punching above its weight.

sal

[Evil D]

Thanx SubMicron,

I have also found that SPY27 for some reason, seems to be punching above its weight.

sal

Anything you can share about the first Spy27/SE option?

[SubMicron]

Just to follow up and clarify something...

Im a big fan of what Larrin is doing at knifesteelnerds.com. Im not discounting his work at all. I bought his book and contribute a little bit every month on Patreon. I encourage all of you to do the same. What he is doing is very important. Demystifying knife steel, and knives in general, is the single best way to grow the knife community. The data that he produces is by far the most accurate and reliable data that's available.

Im also a big fan of others who do edge retention testing. We need more of it. The various YouTube channels that do it with rope and cardboard are very useful. Outpost76 deserves some attention. His dedication level is high and relative to other channels, his tests are relatively consistent.

The problem with testing however is that the results aren't necessarily going to line up with usage... it just depends on whats being cut as well as how and when it gets sharpened.

Thanx SubMicron,

I have also found that SPY27 for some reason, seems to be punching above its weight.

sal

I recall seeing BBB discussing SPY-27 in BladeForums. In fact, his points about it are what sold me on it.

On BladeForums he said:

"I don't feel like folks are appreciating that it will have the finest structure compared to any American, Non Nitrided, CPM Stainless we currently have and will give the ability to run harder with being less prone to chipping and is capable of having less retained austenite translating to a superior overall microstructure for high sharpeness over s35vn with better apexing and burr removal depending on how they HT..."

I have to say that I'm very happy with how it sharpens.

Here's the link to his post on BladeForums. He goes in deep.

https://www.bladeforums.com/threads/new ... t-19499491

[FullScaler]

I am loving it so far. I have only been carrying it for a few weeks but I am trying to put it through its paces by cutting everything from rope, to leather, cardboard, rubber, wood, and anything else I come across.

I am happy with how long the factory edge held up and am even happier with how my first sharpened edge is performing. I have not done any structured testing but anecdotally it feels to perform much better than S30V.

Additionally, I found it to sharpen up quite easily and had a very responsive feel on the stones. It came right back to sticky sharp very quickly.

I've got it out on the boat this weekend and every time I turn around I am finding something new to cut with it.

[Larrin]

What CATRA does not measure is the front end edge retention, especially through non abrasive materials, such as clean cardboard, cloth, tape, plastic, etc.

The CATRA test generates a full sharpness loss curve. It tests every stage including “front end.”

[dj moonbat]

Relative to the other steels OP mentions:

Unlike S30V, 35VN, 20CV, it looks like it will sustain thin geometries. That right there buys you a LOT of edge retention. BD1N handles thin geometries fine when it’s hard (but the HRC thread suggests Spyderco is running it softer than it’ll go), but has less wear resistance than SPY27.

It corrodes more easily than the other steels mentioned. Toughness is about the same as S35VN, which is more than S30V or 20CV.

[Wartstein]

I recall seeing BBB discussing SPY-27 in BladeForums. In fact, his points about it are what sold me on it.
.......
Here's the link to his post on BladeForums. He goes in deep.

https://www.bladeforums.com/threads/new ... t-19499491

Thanks for posting that link (I never visit bladeforums, so I would have missed that post) - indeed very interesting and I´d enourage anyone who is looking into this new steel to read "BBB"s post there.

Another quote from that post that I found really worth thinking about:

"I feel it's refreshing to see a steel that has the potential and focus on edge stability, elasticity and resiliance rather than raw toughness, plasticity (permeant deformation) for shock resistance or carbide blasted, pure wear resistance. I feel its something that has fallin through the cracks over the years for what some folks would really enjoy.

[Karl_H]

Larrin’s articles are probably your best port of call, if you haven’t read them yet:

https://knifesteelnerds.com/2020/01/15/ ... -analysis/

https://knifesteelnerds.com/2020/03/02/ ... -and-more/

+1

However, it should be noted that the SPY 27 Larrin used for testing was not heat treated by Spyderco. Some minor differences between Larrin's heat treatment and Spyderco's heat treatment can probably be expected. That being said, Larrin is the best source of consistent, objective data and metallurgical interpretation for steel comparisons.

The only data point I have seen for Spyderco's heat treatment is one hardness measurement of 62HRC (https://forum.spyderco.com/viewtopic.ph ... &start=140). From what I have been able to discern, the other stainless steels mentioned in OP usually have a measured hardness of ~60 HRC.

[SubMicron]

What CATRA does not measure is the front end edge retention, especially through non abrasive materials, such as clean cardboard, cloth, tape, plastic, etc.

The CATRA test generates a full sharpness loss curve. It tests every stage including “front end.”

Understood.

With a CATRA machine, is there a way to conclude the test at a higher degree of sharpness so the "front end" can be isolated and measured? However... with the Sillica present in the card stock, there may not be a point in doing that, as I suspect that the stack rank would be approximately the same.

I've been wondering what kind of results a CATRA machine would produce if the Sillica was not included in the card stock. My theory is that if the test media were not so abrasive, at least to an extent, the wear produced would be more from the compressive forces of cutting than it would be from the abrasion of the Sillica. This possibly could then give a measurement thats more inclusive of the benefits of edge stability, thereby giving insights to the "front end" performance of a steel.

I should say that I do believe that CATRA tests in their current form are the most accurate measure of overall "edge retention" for people who completely dull their knives before resharpening.

A lot of us though maintain very sharp edges and live almost exclusively in the front end of sharpeness... this is where the fine microstructure steels can be appreciated the most.

[Karl_H]

What CATRA does not measure is the front end edge retention, especially through non abrasive materials, such as clean cardboard, cloth, tape, plastic, etc.

The CATRA test generates a full sharpness loss curve. It tests every stage including “front end.”

Understood.

With a CATRA machine, is there a way to conclude the test at a higher degree of sharpness so the "front end" can be isolated and measured?

Take a look at the graphs that plot Cut Distance (mm) or Total Cards Cut vs Cut #. Just focus on the earlier cuts and ignore the later cuts.
https://knifesteelnerds.com/2018/06/18/ ... etention/

Measuring sharpness using the Brubacher Edge Sharpness Scale (BESS) is probably more useful than using CATRA test cut distance or total cards cut for assessing edge stability.

[Cambertree]

Larrin’s articles are probably your best port of call, if you haven’t read them yet:

https://knifesteelnerds.com/2020/01/15/ ... -analysis/

https://knifesteelnerds.com/2020/03/02/ ... -and-more/

+1

However, it should be noted that the SPY 27 Larrin used for testing was not heat treated by Spyderco. Some minor differences between Larrin's heat treatment and Spyderco's heat treatment can probably be expected. That being said, Larrin is the best source of consistent, objective data and metallurgical interpretation for steel comparisons.

The only data point I have seen for Spyderco's heat treatment is one hardness measurement of 62HRC (https://forum.spyderco.com/viewtopic.ph ... &start=140). From what I have been able to discern, the other stainless steels mentioned in OP usually have a measured hardness of ~60 HRC.

Yes, agreed - there would certainly be some minor differences from Larrin’s small scale custom knife type heat treatment and Spyderco’s production heat treatment.

Given that Larrin tested a range of austenitizing and tempering temperatures and cryo/no cryo/household freezer etc, I’d be surprised if his input on optimum heat treat procedures for a good balance of properties, wasn’t also sought and taken on board by Spyderco’s heat treaters.

Wartstein: Thanks for that quote from BBB. I hadn’t seen the original post over on Bladeforums, as I only visit there infrequently, these days.

The properties Shawn mentioned in that quote are exactly the kind of qualities I would like in a bladesteel.

[Larrin]

Understood.

With a CATRA machine, is there a way to conclude the test at a higher degree of sharpness so the "front end" can be isolated and measured? However... with the Sillica present in the card stock, there may not be a point in doing that, as I suspect that the stack rank would be approximately the same.

I've been wondering what kind of results a CATRA machine would produce if the Sillica was not included in the card stock. My theory is that if the test media were not so abrasive, at least to an extent, the wear produced would be more from the compressive forces of cutting than it would be from the abrasion of the Sillica. This possibly could then give a measurement thats more inclusive of the benefits of edge stability, thereby giving insights to the "front end" performance of a steel.

I should say that I do believe that CATRA tests in their current form are the most accurate measure of overall "edge retention" for people who completely dull their knives before resharpening.

A lot of us though maintain very sharp edges and live almost exclusively in the front end of sharpeness... this is where the fine microstructure steels can be appreciated the most.

I wrote quite a bit about initial sharpness loss vs long term in this article: https://knifesteelnerds.com/2018/11/26/ ... etention2/

There is no particular reason why “front end” sharpness loss would be less affected by wear than any other part of the test. Wear affects fresh edges and dull ones. It is certainly possible for edges to dull from rolling or chipping as well depending on how they are being used. Because most of the reported cardboard testing shows an improvement from increased hardness it is either dulling to wear, deformation, or both. Otherwise increased hardness would lead to reduced edge retention from micro-chipping. If wear then it will correlate strongly with the CATRA test. If deformation it will correlate with hardness (largely independent of steel). If mixed then it will correlate to a combination of the wear measured in the CATRA test and the resistance to deformation measured in a hardness test.

There is more scatter in testing the less sharpness loss is tested. In other words, if you’re testing BESS scores starting from hair whittling edges to 100g or so the testing is highly variable and very dependent on initial sharpening. The effect of tiny burrs would be huge, for example. Finding any hard conclusions would require many re-runs and possibly blinded testing. Certainly a YouTube tester looking at one test each between two knives with a subjective stopping point would have questionable value. But with many retests or many different steel/hardness combinations something could emerge in terms of a trend if an objective testing method could be developed.

I know in my testing I can see the effect of variability in sharpening on early edge loss but the broader trend is visible in terms of correlation between initial sharpness loss and testing to dull. Wear doesn’t switch to some other mechanism just because the edge is less sharp.

[Wartstein]

Double post, sorry..