CPM MagnaCut | Edge Performance

[Deadboxhero]

That was indeed interesting, thank you DBH. The CRUWEAR PM2 was already a must-buy item after tax season, but even more so now. I have the sneaking feeling my old CRUWEAR Millie is harder than my Z-Wear Shaman, but they are different beasts so it’s a tough thing for me to be sure about. I’m eager to see any testing in the new MagnaCut-equipped Native 5 Salt!

You know, bias is a mother, there's no way to know if it is harder unless you test its hardness, I think the problem with sharing detailed stuff like this hardness on the pm2 Cruwear is that now folks may have the impression that all cruwear is run harder as some special quality of cruwear over zwear.

That is incorrect, they all can get hard and respond similar to heat treatment because they are analogs, rather than completely different steels.

I have a custom knife in Z Wear I heat treated to 65rc, Cruwear will respond the same. So I don't think of them as being drastically different as much as they're just being statistical scatter from the volumes made.

[Deadboxhero]

Interesting info, thanks for posting. From Larrin's introductory material on MC, it was apparent that for it to shine in smaller knives it really needed to be in the higher hardness range, maybe 63 - 64, this seems to back that up. I suppose the production variance mentioned illustrates one reason why there can be so much noise in user perceptions. Someone who, by luck of the draw wound up with a 61 HRC MC PM2 is less likely to be impressed with edge retention compared to someone who received a 63.5 HRC copy, they would have higher toughness, but the difference there is probably harder to notice in everyday pocket knife use.

Hopefully upcoming Spyderco MC production variance can be controlled well enough that most folks can get a copy with hardness somewhere in that 63-64 sweet spot.

I agree I think the higher hardness on Magna Cut for a small pocket knife would be nice. I think one thing that people need to take in consideration is that since we are using a "magnifying glass" to look at these products and we aren't testing products from other companies they'll get the impression that the other companies products are better because there's not a magnifying glass on them highlighting any flaws.

Well, I have to care about the product and it has to be good for me to even want to test it.

Some of the other products I've experienced from other producers don't make the cut and I don't share because "shiny footprints."

[Deadboxhero]

Thank you DBH for your time, effort and willingness to share.

Thanks man I appreciate it.

[Deadboxhero]

Thank you Shawn! I particularly appreciate your emphasized commentary on controlling variables such as precise adge angle, acquiring a crisp & deburred edge with undamaged steel. As consumers I feel we get hung up on the purchasing of scientific stats and qualities and lose sight of the profound impact our own contribution (sharpening) makes!
Your comment on 52100's tolerance of mediocre sharpening is profound in its implications.
I for one will be "honing" my sharpening skills even further this year.
Thank you for the inspiration!

Thank you, yeah it's something I've talked about with Michael Christy, how the sharpening makes all the difference and it's sometimes difficult to watch claims being made about "this or that" when the sharpening hasn't been ruled out.

If you want the sharpest, highest performance knives show me your sharpening equipment, abrasives and your technique and that will tell me everything.

Yet, I think a big part of the community is chasing the names of all these different steels more than they are chasing the attributes of these steels and synergizing the edge for maximum performance.

Just my opinion, hope it doesn't ruffle any feathers.
I'm just speaking freely.

[Woodpuppy]

That was indeed interesting, thank you DBH. The CRUWEAR PM2 was already a must-buy item after tax season, but even more so now. I have the sneaking feeling my old CRUWEAR Millie is harder than my Z-Wear Shaman, but they are different beasts so it’s a tough thing for me to be sure about. I’m eager to see any testing in the new MagnaCut-equipped Native 5 Salt!

You know, bias is a mother, there's no way to know if it is harder unless you test its hardness, I think the problem with sharing detailed stuff like this hardness on the pm2 Cruwear is that now folks may have the impression that all cruwear is run harder as some special quality of cruwear over zwear.

That is incorrect, they all can get hard and respond similar to heat treatment because they are analogs, rather than completely different steels.

I have a custom knife in Z Wear I heat treated to 65rc, Cruwear will respond the same. So I don't think of them as being drastically different as much as they're just being statistical scatter from the volumes made.

The other variable in my comparison is that the Millie has been sharpened many many more times that the Shaman. Am I all the way through the affected steel of the “factory edge” on the shaman yet? I’m confident I am in the Millie.

[JRinFL]

Yet, I think a big part of the community is chasing the names of all these different steels more than they are chasing the attributes of these steels and synergizing the edge for maximum performance.

Just my opinion, hope it doesn't ruffle any feathers.
I'm just speaking freely.

I've been guilty of that early on, but thanks to you, Larrin, Cliff, vivi, and others I've been learning. No feathers ruffled here.

[JSumm]

Shawn, thanks for all this work. It is very educational to follow along.

I think the reason I like SPY27 so much, is the ease of sharpening with my equipment combined with my relatively new at hand sharpening skills or lack there of. I get a great response with it, and it seems to hold it longer than anything else I have experienced with similar ease in sharpening.

[Deadboxhero]

Shawn, thanks for all this work. It is very educational to follow along.

I think the reason I like SPY27 so much, is the ease of sharpening with my equipment combined with my relatively new at hand sharpening skills or lack there of. I get a great response with it, and it seems to hold it longer than anything else I have experienced with similar ease in sharpening.

Yeah the sharpenability is really nice on the Spy27.
My Para 3 LW was 62.0rc which was nice.

I'd like to get a SPY27 Pm2 in the future for testing.

[Godzilla68]

I’m always impressed by the amount of work and time people like DBH put into these tests. Thank you for your contribution and please keep educating us all.

[Larrin]

I love the testing.

[Deadboxhero]

I love the testing.

Thanks Doc

[Deadboxhero]

I’m always impressed by the amount of work and time people like DBH put into these tests. Thank you for your contribution and please keep educating us all.

Thanks man, when time and money allow, I love to share.

[RustyIron]

Just my opinion, hope it doesn't ruffle any feathers.

If you're not ruffling feathers,
you're not saying anything of consequence.

Keep up the good work.

[ZrowsN1s]

I talked to you about getting a goniometer a few months ago, and you gave me some good recommendations. But then I balked at the price of international shipping. I finally bit the bullet and ordered one tonight.

[ab_initio]

This is a tremendous effort and hugely valuable to the knife community. I'd really like to see the incorporation of the BESS testing and goniometer to all the community/knifetube testing. It is something that I can reference when testing my knives, and we know a lot more about what the particular specimens in each test actually accomplished that just can't be repeatable represented through "hair whittling" "Hair shaving" "paper slicing", etc. grades.

Unless of course somebody wants to start selling their hair as a reference test medium!

Cheers

[metaphoricalsimile]

@Deadboxhero are your data points based on a single sample, or do you have sample replicates? If you have replicates do you have copies of your graphs with error bars? Thanks for doing all this work and for the good science on display here.

[salimoneus]

Interesting that M390 seems to have made a very good showing in comparison, unless I'm reading the charts wrong. Didn't Dr. Thomas say that he wasn't especially fond of M390? I'm pretty sure I heard him say that in an interview recently. I wonder why, since it seems to be such a good performer in this and many other tests I've seen. Sure I understand it's an older steel, and mostly yesterday's news, but it still performs very competitively.

[sal]

Hi Shawn,

Very nicely done! Much appreciated. Also Larrin, thanx much for your sharing.

Good stuff.

sal

[metaphoricalsimile]

Interesting that M390 seems to have made a very good showing in comparison, unless I'm reading the charts wrong. Didn't Dr. Thomas say that he wasn't especially fond of M390? I'm pretty sure I heard him say that in an interview recently. I wonder why, since it seems to be such a good performer in this and many other tests I've seen. Sure I understand it's an older steel, and mostly yesterday's news, but it still performs very competitively.

Larrin Thomas prefers steels that have a good ratio of wear resistance to toughness, and in his testing M390 has not had good toughness relative to its wear resistance.

[Matus]

Thanks a lot Shawn, some really interesting results. I completely agree, MC deserves to be HTed to higher hardness - at leas for pocket knives.

One point (a thought, really) about that 'better initial sharpness holding' for low alloy steels:

I can not really attest to it, but my impression is that it mainly comes from the world of Japanese and western custom kitchen knives - and there the situation is a lot different to what we see in pocket knives in the past few years. First of all - it is different companies with different technical background who make the knives (from very traditional methods where HT is done by eye to sophisticated automatized HT processes by others). Also - with exception of few outliers (like yourself ) high alloy steels are not really used much for these knives. For a very long time it was basically only simple carbon steels being used like white or blue 1/2/super for the large part the grind and sharpening were over time implicitly fine tuned to the properties of these steels and the use of these knives. Later industrial production arrived and more and more different stainless steels entered the market - and these were not always HTed properly. The best example would be VG-10 which never really took off among enthusiast users, because the knives that were widely available (mainly by Shun) had issues with chipping (my personal experience too).

On top of the different steel/grind 'landscape', the medium being cut in the kitchen is on average a whole lot less abrasive and aggressive to the edge then a manila rope, cardboard, or a zip-tie. And I am wondering whether this could yield to slightly different edge dulling processes where the edge of the low alloyed steels fares better.

Last but not least - one often hears how stainless steels in kitchen knives don't react to higher grit stones (say above 3k, give or take) as the simple carbon steel knives do - let alone to very fine natural sharpening stones. How much of that is just an objective fact that stainless steels have different carbides in them and how much is the sharpening itself (where most users have tuned their process to carbon steel knives) is not simple to disentangle, but may well contribute to this 'better initial sharpness holding' conundrum.

Again, just a though. Thanks again for your work.