CTS-HXP vs M390

[MadRookie]

Hi Hans:

I live in Cape Town, South Africa.

Have 2 Benchmade folders in M390 - brilliant stuff.

Also waiting for my Blue PM2 in M390 from Bentobox...

:)

[speedcut]

I respectfully disagree. A polished edge excels only in pushcuts and it will kinda slide over fabric.

Opsss...seems i got it wrong.....Thank you Chuck..learning something new every day...

[KardinalSyn]

Good info here for me too. Cant wait to get my Para2 in XHP in April.

[Brock O Lee]

Hi Hans:

I live in Cape Town, South Africa.

Have 2 Benchmade folders in M390 - brilliant stuff.

Also waiting for my Blue PM2 in M390 from Bentobox...

:)

Hi Rookie,

Welcome to the forums...

Apparently Spyderco's M390 is run at a higher RC than BM, so this one should be great... Any day now :D

Good luck with your wait...

[BAL]

Nothing to add, just thanks for all of the info, very intesting. Ankerson, you do great work.

[Niles]

Has anyone checked the RC of the PM2 in M390 yet?

[Blades]

Yeah that should leave a nice aggressive edge. :)

Thanks, nice to have it verified.
Your polished mirror edge is still a thing of beauty, and one of these days I'm going to drive up and visit ya.
Maybe put a mirror edge on the blade, and a few strokes on a medium stone so it will cut as well as it looks.

[Niles]

Thanks, nice to have it verified.
Your polished mirror edge is still a thing of beauty, and one of these days I'm going to drive up and visit ya.
Maybe put a mirror edge on the blade, and a few strokes on a medium stone so it will cut as well as it looks.

I think that's the best solution...polished back bevel with a slightly aggressive edge like Ankerson suggests. Bites and glides.

[xavierdoc]

I think that's the best solution...polished back bevel with a slightly aggressive edge like Ankerson suggests. Bites and glides.

I reckon this is why my investment cast 440c Serrata seems to cut so well. I've seen images of the edge and it has the appearance of micro-serrations (I know any steel will look this way at high enough magnification). This wasn't a scanning electron microscope it was a laser scanning confocal microscope (using digital tomography to create a surface map): it showed the columnar grain at the edge. I don't know much about these things but I do know that the blade seemed to cut better than any of my other 440c knives. Not scientific but it got me thinking.

[Blades]

Most steels will do MUCH better with a coarser edge, something in the 14-16 Micron range, with a polished edge based on my testing you lose around 40% to 50% edge retention with every steel that I have tested so far in direct comparison.

BUT....

Go too coarse and the same issue happens as with the Polished edge.

Something right in the middle as I said give or take would be optimal for cutting efficiency and edge retention.

For those with an Edge Pro the 600 Grit stone would be it.

2000 Grit Japanese Water Stone.

Fine Norton SIC then stropped on a SIC loaded strop (Smooth Side).

400 grit Congress SIC Stone.

The higher Alloy steels will handle a polished edge better than the lower alloy steels due to the higher percentage of Carbides.

So where do I find an inexpensive 2000 grit water stone? :D Time for ebay.

[Blades]

So where do I find an inexpensive 2000 grit water stone? :D Time for ebay.

Nevermind, I can get an unmounted Edge Pro 600 grit stone for $8.00(plus shipping).

[bh49]

Nevermind, I can get an unmounted Edge Pro 600 grit stone for $8.00(plus shipping).

or get 400 grit Congress SIC Stone for the half of it.

[rlm1159]

Spyderco newbie here :D

Thanks for the great information and tips, everyone.

[daberti]

I think XHP will hold the razor edge a little longer than M390. But m390 will hold its working edge a lot longer. I am going from what I have read though. Im yet to experience both. (I can tell you more on m390 around tuesday )

Really?? Come on mate.
CTS-XHP is no other than 440XH, a 440C variant with higher C content 1.6% and very small V, Ni, Mo contents (0.5% each). If taken up to 63HRC Cr will be tied up in Chromium carbides leaving less free Chromium for stain resistance purposes.
M390 is another story: 1.9C, 4%V, 20%Cr, 1%Mo, 0.6%W. If taken properly (and I cooperated with Elliot Williamson to achieve that) to 63HRC it will double XHP@63 as far as edge holding is concerned. Not to mention its stain resistance and toughness, well above 440C@58, s30v@60, s35vn@62, s90v@59 and yes, even CTS-XHP.
CTS-XHP holds one single advantage: more forgiving as far as heat treatment is concerned.

[Guy Vanderveken]

My XHP Millie takes a lick on the 600 DMT and still shaves, races through paper- news paper, I really prefer the ease at which it allows me to hone that edge, much like RWL34(CPM154), its bite and ease of working I am really enjoying, I did not really enjoy my Mule(M390), I was disappointed with its edge holding and found it a bit long in the tooth to hone. I have a custom M390 folder at 61.2 RC with double cryo temper cycle- it performs, but is heavy on the touch up.

I believe the question was refering to EDC, between the two for myself hands down XHP is great, I am in the process of getting rid of all my High Vanadium Alloy knives(except the customs), as I am starting to use my knives a lot more now, plus touch them up on the DMT/spydie ceramics and strop(loaded with metal polish). I am still a fan of ATS 34,N690 and D2, the powder versions of these for me are great.

I just want to thank the guys on this forum who have always given so much information on sharpening- thank you, you guys are an inspiration
If you drop the angle of your back bevel, polish it a bit, put working edge and micro bevel on the edge, then this thank you is directed at you, you guys got me from the playing with my knives to the working of my knives.
Cheers

[Ankerson]

Thanks, nice to have it verified.
Your polished mirror edge is still a thing of beauty, and one of these days I'm going to drive up and visit ya.
Maybe put a mirror edge on the blade, and a few strokes on a medium stone so it will cut as well as it looks.

Yeah you aren't that far away really, still a drive though. :)

[phillipsted]

A lot of us have said this many times - but I'm a firm believer that rules regarding sharpening (e.g., 600-grit vs polished edge) depend on a wide variety of other factors, including the cutting task being performed, edge geometry, relative humidity, phase of the moon, etc... :cool: Jim, I applaud your work to standardize your measurements around a single style of cutting task - that is the only way to even attempt to get scientifically valid numbers.

So for cutting rope and cardboard, slicing vegetables, and other "household" tasks, I'd agree that in my experience a coarser or toothier edge will provide better cutting performance.

However, in my experience, certain tasks are much more easily accomplished with a highly polished edge - such as cutting cloth, opening envelopes, tracing paper templates, and precision fitting of wood components in the workshop.

There are so many variables - that's part of what makes this a fun hobby!

TedP

[daberti]

Given the heat treatment this is expected.
M390 gives its best with high austeniting/tempering temperature. The grain size is very small and uniform and this is true for carbides as well.
I'm talking about exploiting the secondary hardness range, which to my understanding has been done only by Neels Roos and Elliot Williamson so far

My XHP Millie takes a lick on the 600 DMT and still shaves, races through paper- news paper, I really prefer the ease at which it allows me to hone that edge, much like RWL34(CPM154), its bite and ease of working I am really enjoying, I did not really enjoy my Mule(M390), I was disappointed with its edge holding and found it a bit long in the tooth to hone. I have a custom M390 folder at 61.2 RC with double cryo temper cycle- it performs, but is heavy on the touch up.

I believe the question was refering to EDC, between the two for myself hands down XHP is great, I am in the process of getting rid of all my High Vanadium Alloy knives(except the customs), as I am starting to use my knives a lot more now, plus touch them up on the DMT/spydie ceramics and strop(loaded with metal polish). I am still a fan of ATS 34,N690 and D2, the powder versions of these for me are great.

I just want to thank the guys on this forum who have always given so much information on sharpening- thank you, you guys are an inspiration
If you drop the angle of your back bevel, polish it a bit, put working edge and micro bevel on the edge, then this thank you is directed at you, you guys got me from the playing with my knives to the working of my knives.
Cheers

[Cliff Stamp]

I'm talking about exploiting the secondary hardness range, which to my understanding has been done only by Neels Roos and Elliot Williamson so far

Why would you want to do that exactly?