so . . . how best to sharpen N690Co ? Which stones most effective ?

[Wowbagger]

Looks like starting a new thread is the way to go with this. I was asking over in the Pattada thread but she's deader than a ________ fill in the blank.

Most of the reason I am posting is I have searched quite a lot here going back to like 2002 discussions of N690Co and I haven't found much in the way of discussion of which stones this steel likes best.
Will Norton water stones do it ? I'm thinking this may be the best way to go for deburing.
Do I need Shapton Pros ? Is that going to cut the steel most efficiently rather than glaze the stone ?
Sure Shapton Glass is going to be better but necessary ? Will these take the bur off as well as the old Nortons ?
How will the steel respond to my Spyderco Ultra Fine Triangle ceramic rod ? I am thinking it will raise a bur but not cut it off.

I could be finding out by experimentation but I want to use the knife edge as it came from Italy first for what I can learn from the factory edge.

so . . . how best to sharpen N690Co ?
Comments ?
Jason to the rescue ?

The N690Co is the longer knife in this photo.

 

[Obsessed with Edges]

N690Co is essentially similar to 440C (~ 1% carbon, 16-17% chromium). I think some have also compared it closely to VG-10, with it's additional cobalt content. I don't use water stones, but I'd think if you've got something that's worked for you with either of these two steels, it should handle the N690Co pretty easily.

 

[Alberta Ed]

Diamond hones work well on VG-10, a very similar steel, as well as any of the very high carbide content 'super steels'.

 

[aleforme]

In regard to the Spyderco UF. I use this stone on VG-10 all the time and love it. Assuming N690 would be very similar. I can get a beautiful polished edge with it. Not sure it will raise a burr that easily or cut it off. I mainly just use the UF to refine the edge and give it a nice polished look. You have to be careful though. A few bad form draws and the edge suffers easily.

 

[M-S-T]

N690co is basically a European analog of VG10 with a little bit more of chrome. It comes around 58-60 HRC with up to 62 HRC with cryo. You can use anything from norton to shapton glass with no problems.

 

[JJ_Colt45]

Agreed it isn't bad to sharpen ... you definately don't need Shaptons to sharpen it ... I love my Shaptons but if you like Norton's they should work fine ...

I like Nortons Combo India Stones or Choseras for my VG10 and they seemed to work well with the one N690Co blade I had ...

I usually just touch up with 1200 grit round ceramic rods so your Spyderco Triangle should work for touch ups also ...

JJ

 

[Wowbagger]

Thanks !
I'll still take more info.
I like details and minutia.

From trimming hard rubber the last couple days I am seeing some scratches in the sort-of-polished bevels in the area of the blade that I use for trimming. I don't get that with M4.
I was concerned this stainless was going to be kind of soft. It is doing a good enough job trimming however.
I was thinking initially from what I read about N690Co that it was a kind of ~super stainless meaning rust resistant not super like S110V. Then I was reading that 440C is more stain resistant.
?
Doesn't matter to me ( the rust resistance ) I bought the knife for the handle shape and blade length.
The last time I saw scratching of the blade like this though was in H1 (non serarated).

N690Co is a new experience for me.

 

[Wowbagger]

I love my Shaptons but if you like Norton's they should work fine ...

Oh I do like the Shaptons a lot. It is just that some times with the softish stainless the softer Nortons take the bur off easier.

Another day or two and I will be sharpening the Pattada. I will learn more then.

 

[McFeeli]

N690 performs very much like VG10, sharpens up like VG10 too. If I were so inclined to, I could start and finish on 1k and be satisfied with the results. It's an easy steel to deal with(especially if you're used to S110V).

 

[Wowbagger]

Well that didn't go the way I thought it would.
In a good way ! ! !

I know what you all said "Sharpens like VG10".
I was just sure I was going to get this invincible foily bur.

Lets back up. First I chucked up the Shapton Glass stones into the Edge Pro.
Set the angle to hit the convex edge bevel right in the middle of the bevel. I wasn't going for a shallower or wider angle; I just wanted to basically keep the stock geometry which seems good and the edge at the tip seems so frail and I knew the bevel tends to get wider / maybe shallower way out there in the tip and I didn't want all that to get more weak.

Using the 220 I got the roundy convex flattened out and apexed the edge. The steel seams to really kind of load up the stone and stick to it. I used my natural Nagura quite often to keep the stones cleaned out.

I went to the 500 and by the time I was using the 1000 the bur was very minimal and disappearing nicely on it's own.
By the time I was using the 4000 I was thinking I had made an error and wasn't down on the edge but back a ways on some kind of minuscule convex or something ?

I told my self to have faith . . . to trust the mighty Edge Pro. I know that if I just go step by step all will be well.

I got to light strokes, one or two pulls per side (just the length of the stone to pull from the plunge grind of the edge to the tip.
Rinse it off and pat it dry(ish)
Look for the bur . . . where's the bur ? ? ? ? . . . I see a little trace here and there of kind of dusty like fragments on the edge . . . where's the bur ? ? ? . . . oh mannnnnn . . . I'm going to have to reset the guide for a micro bevel (I HATE DOING THAT) . . .
Then flip the knife.
Look for the bur . . . where's the bur ? ? ? ? . . . I see a little trace here and there of . . .

. . . have faith in the mighty Edge Pro.

I washed the knife under the faucet. Very gently blotted it dry.
Took the edge to a hair in my arm . . .
and . . .

Hair whittling !
I like this STEEL !
N690Co and I might could be friends.

 

[Obsessed with Edges]

The 'sharpens like VG-10' description can be tricky, depending very much on which maker's VG-10 one is talking about. In terms of tough, tenacious burrs, VG-10 can be a pain in removing them on blades that aren't heat-treated quite as hard, such as with many of Spyderco's knives in this steel. But taken a couple or three RC points higher, and a lot of those burring issues aren't so bad anymore. I have sort of a love/hate relationship with VG-10, for this reason, depending entirely on which knives I'm dealing with.

Good to hear it all went smoothly.

 

[Wowbagger]

a couple or three RC points higher

Wow !
Three points is a whole lot of difference.
I would never have guessed Spyderco would go that much softer than they had to. Other companies maybe but not Spyderco.

Thanks for pointing that out as far as there being some softer versions verses harder versioms.

 

[M-S-T]

.

 

[Obsessed with Edges]

Wow !
Three points is a whole lot of difference.
I would never have guessed Spyderco would go that much softer than they had to. Other companies maybe but not Spyderco.

Thanks for pointing that out as far as there being some softer versions verses harder versioms.

I originally tried VG-10 from Spyderco (Endura 3/4 models and others), in maybe the mid-late 1990s - early 2000s time frame. Not sure to what hardness they took those blades, but I suspect they didn't go much past RC 57-58 or so. Very annoying burring, especially coming off ceramic hones, and at the time, many were noticing & complaining about how easily the edges seemed to roll on them (I noticed this too).

At some later time, I acquired blades from A.G. Russell (HRC ~ 59-60 or so) and Mcusta (Laminated damascus w/VG-10 core), and the difference in sharpening, as compared to the Spyderco blades, was night & day. Still some burrs formed in sharpening them, but they were much easier to clean up, not being so tenaciously ductile (flipping back/forth all day) as with the Spyderco blades. That opened my eyes, and made be rethink my opinion of the steel as a whole.

I think some very high-end kitchen knives in VG-10 might be treated up to maybe HRC ~ 62 or so. In reading about them here and elsewhere, they might be more vulnerable to chipping, as opposed to burring, depending on what tools are used to sharpen them up. But I think the 'sweet spot' for VG-10 probably lives in the HRC ~ 60 neighborhood or so.

 

[Wowbagger]

.

M-S-T,
Yours is the briefest post I've seen.
Care to elaborate ? Or does "." say it all and I'm too dense to grasp it ?

 

[Wowbagger]

I think the 'sweet spot' for VG-10 probably lives in the HRC ~ 60 neighborhood or so.

I wonder what the N690Co is in my Pattada. Was it listed and I missed it ?
Sal ?
Good stuff in any case.

 

[Blues]

M-S-T,
Yours is the briefest post I've seen.
Care to elaborate ? Or does "." say it all and I'm too dense to grasp it ?

Apparently he's made his "point" and nothing further need be said.

 

[Wowbagger]

Apparently he's made his "point" and nothing further need be said.

 

[Obsessed with Edges]

I wonder what the N690Co is in my Pattada. Was it listed and I missed it ?
Sal ?
Good stuff in any case.

I'm not finding it either.

Seems like Spyderco has rarely published the RC hardness values of their blades. Over the years, many on the Spyderco forum have lamented that fact in posts there, or at least tried to ask why(?) they don't publish it (I don't think that's been answered either). So far as I know, not much has changed in that regard.

To some extent, I sort of understand it, because it gives a maker some leeway to fine-tune & improve their process as they go, without having to further justify any perceived changes in the published specs along the way. It's only the steel junkies & sharpening fanatics like us who care about these things, and I'm betting we're in a small minority. Most of the knife-using world won't understand what the numbers actually imply, or even care, so long as there aren't any obvious defects in how a knife performs in normal, everyday uses. My Spyderco knives in VG-10 were purchased 10 - 20 years ago, so maybe they've since tweaked some improvement into their more recent knives in the steel, hopefully.

The questions about VG-10 came up when users started comparing Spyderco VG-10 to other makers' treatment of the steel (often at known/published values for hardness). And then burring/edge-rolling tendencies became obvious and impossible to ignore in some of the Spyderco knives, as compared to the others; issues like very quick dulling or edge-rolling issues when cutting simple stuff like cardboard or nylon rope, as I noticed with some of mine.