# Stone for high alloy steels



## HSC /// Knives (May 17, 2021)

Curious what you all use or recommend to sharpen your High alloy steel kitchen knives ( for example your PM steels)

I’ve been using a king neo 800 to start with, but I’m not sure that I am in love with it. 

I need to get a stone out here in France. 

Thanks


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## inferno (May 17, 2021)

i can confirm that shapton glass and pro work well with s30v, srs15, r2. 
i like the 3 and 4k from the glass line and the 2k from the pro line. the 1k pro is also good.


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## branwell (May 17, 2021)

If you are talking about steels with high concentrations of Vanadium Carbide, once the scratch pattern is fine enough that its not gouging out the carbides, you need to switch to Diamond plates or lapping film to really get a keen edge. If you don't, you will end up abrading the softer matrix around the carbide which will result in an, hmmmmm, interesting edge which might or might not be to your liking.
See attached article with SEM images showing said abrasion using a Shapton Glass 8K and other images showing a JNat.

If you are talking about the rest of the PM steels, many are pretty wear resistant so fast stones will make life easer. The usual suspects like Shapton Glass, Nani Pro / Choseras will work. That said, at the grit range you mention, by far the fastest stones I have that are not diamonds are the Nubatama Ume 1K and 1K Platinum.









Carbides in Maxamet


Carbides in steel are often compared to gravel in concrete. While there are some parallels, such an improving wear resistance, the analogy fails in the prediction that carbides can “pop out&#…




scienceofsharp.com


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## Slim278 (May 17, 2021)

Most wear resistant I have is CPM 3V and the Naniwa Chosera stones I have work fine. Some Shapton pro or glass should also work fine.


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## refcast (May 18, 2021)

For what its worth I like the shapton glass 500 more than the jki diamond 1k for carbide-y or heavily stainless steels. The shapton glass cuts faster, leaves more even scratches for its grit, and gives better feedback for me. Using the the diamond 1k can feel a bit scratchy . . . .it's like diamond plates but with the gaps filled it, so it's smoother, but it's not as well-filled as the the ceramic stone. . It still feels like the individual diamonds can gouge, so good use of pressure is key to keeping the scratches less deep. . . the surface burnishes over time, so it slows a bit and cuts more evenly.

The shapton glass is a bit thirsty in the first couple minutes, and benefits from regular wiping off the swarf with water to keep on cutting. The surface is very grippy on metal, the most grippy of a stone I've used so far. . . which isn't a gigantic number, but still. I've been to JKI to try their stones, so even compared to that, this is more grippy.


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## ian (May 18, 2021)

FWIW, Sigma stones are supposedly made for high alloy steels. I've never had any such knives, so I never tried the Sigmas I had on them.


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## refcast (May 18, 2021)

I got a sigma 120 from MTC LA in person (green box. . . I'm not sure which version that means, though). They didn't have it online, but they had it in the showroom . . . maybe if you call they might ship it. They also didn't have shapton glass in stock, even though it was on the site. . . 

It feels similar to other super low grit silicon carbide stones. It starts off pretty harsh and fast cutting and mellows as the grit smooths over. Haven't used it enough to see how it clogs and dulls more though. I'd but this in the gouge-ing category of stones, but the grit is consistent and I like it better than the pink brinks stuff. The stone cost around $36, so its about the same price or a little cheaper than a pink brick.

So - great for thinning. I haven't tried the shapton pro 120 slurry refresh trick yet, so I can't compare those two much yet, but I have them now.


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## Barmoley (May 18, 2021)

refcast said:


> For what its worth I like the shapton glass 500 more than the jki diamond 1k for carbide-y or heavily stainless steels. The shapton glass cuts faster, leaves more even scratches for its grit, and gives better feedback for me. Using the the diamond 1k can feel a bit scratchy . . . .it's like diamond plates but with the gaps filled it, so it's smoother, but it's not as well-filled as the the ceramic stone. . It still feels like the individual diamonds can gouge, so good use of pressure is key to keeping the scratches less deep. . . the surface burnishes over time, so it slows a bit and cuts more evenly.
> 
> The shapton glass is a bit thirsty in the first couple minutes, and benefits from regular wiping off the swarf with water to keep on cutting. The surface is very grippy on metal, the most grippy of a stone I've used so far. . . which isn't a gigantic number, but still. I've been to JKI to try their stones, so even compared to that, this is more grippy.


Interesting how different the experiences can be. I used JKI 1k diamond on m390 and 10V among other, simpler steels and found it very good. Gave me very even scratch pattern and cut these steels well, didn't find it scratchy at all. I used the nagura that comes with it before sharpening. Haven't used shapton glass 500 though. 500 vs 1k is pretty big difference though, so maybe that is part of it.


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## refcast (May 18, 2021)

The scratch pattern I agree is very even and fairly uniform in depth. . . . I wonder if there's a better description than scratchy . . . I guess deeper scratches should suffice.

For instance, Gesshin 1K soaker scratches are a bit less deep I feel. The diamond 1k is a pretty good stone though. . . maybe I need to take more time to do a comparison, then.


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## Nagakin (May 19, 2021)

I used a shapton glass 500 double thick, shapton pro 2000, and a raw leather strop without compound for zwear with diamond paste to refresh. Just deburring after 500 with a jnat kept a stupid long edge.


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## Benuser (May 19, 2021)

In Europe, Shaptons Pro and Glass and Naniwa Professional certainly match. All available with knivesandtools.fr








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## M1k3 (May 19, 2021)

If you want to be able to sharpen any high carbide steel without issue, diamond would be your best bet.


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## big_adventure (May 19, 2021)

It depends on the steel, really. I use Chosera stones on SG2 and ZDP189 and they work fine. Slower than the same work on aogami, but only by a couple of minutes. 

I haven't tried steels with massive amounts of vanadium or tungsten carbides however - i hear that things like REX121 and Maxamet prefer diamonds.


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## HumbleHomeCook (May 19, 2021)

4%+ Vanadium Carbide content and you need diamonds. Especially beyond around 600 grit.


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## SolidSnake03 (May 19, 2021)

Depends on what you are looking for in terms of splash and go vs soaker vs diamond. After a boat load of trial and error I’ve found that diamonds leave the best edges on my pm steel knives. By best I mean longest lasting, toothy, cleanly apexed and do that job fast and efficiently. That said all my recommendations below have worked fine on pm steels.

Also if you have the $$ there is nothing like the Super Vitrified Diamond stones. Very expensive but stunning performance, absolutely the best cutting thing I’ve used regardless of price and eat Maxamet like nothing else short of a full on grinder.

Stuff that works on pm up to/including zdp-189 that I’ve liked
Soakers : King Hyper stones (all of them), Sigma Select 2 240 and 1k
Splash and Go : Shapton Pro/Glass, Chosera, Sigma Select 2 400, 3k and 6k
Diamond : Atoma plates, Venev Diamond Plates
Super Vit : JKI has an 800 grit, TripleB handmade has a whole line and Practical Sharpening

Off all the regular stones id pick the Sigma Power Select 2’s if you just care about cutting and cutting fast/well but don’t want to use diamonds. The 1k especially is a monster.


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## HumbleHomeCook (May 19, 2021)

"Powder metallurgy" doesn't really have any bearing on the sharpening discussion. That is just a method of producing the alloy that results in very fine grain structure. Hardness is also only an indicator and only tells us just so much.

It's the alloy content that is predominantly relevant, specifically the type of carbides formed in the steel. For example, BD1N and Ginsan are PM steels and both are easy to sharpen. ZDP-189 gets it's hardness from extremely high levels of chromium carbides. These carbides can be abraded by silicon carbide and aluminum oxide. Vanadium carbides cannot and require diamond/CBN. It's physics. Below about 4% vanadium carbide content, there isn't really enough and they are often small enough, to not have that big of an impact so you can get away with SiC or AlO. But beyond that, and once moving past about 600 grit, you need something harder than the carbides to abrade them.


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## Barmoley (May 19, 2021)

Practical Sharpening vitrified diamond stones is my recommendation especially in France. I had good experience with JKI too, but shipping might be an issue. Haven’t tried JKI 800 or BBB stones, but both are excellent by all accounts if on the expensive side.


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## kayman67 (May 19, 2021)

ian said:


> FWIW, Sigma stones are supposedly made for high alloy steels. I've never had any such knives, so I never tried the Sigmas I had on them.


They work great. But pretty much the opposite with some other alloys.


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## ian (May 19, 2021)

kayman67 said:


> But pretty much the opposite with some other alloys.



What does this mean?


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## kayman67 (May 19, 2021)

EG, 2000 was a faded performer with some random German knives (Wusthof, Zwilling...), so much so that no real sharpening was going on. Took me a while to realise what's happening.


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## Deadboxhero (May 19, 2021)

HSC /// Knives said:


> Curious what you all use or recommend to sharpen your High alloy steel kitchen knives ( for example your PM steels)
> 
> I’ve been using a king neo 800 to start with, but I’m not sure that I am in love with it.
> 
> ...


Harbeer, Are you finishing with a diamond loaded leather strop at all?


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## Deadboxhero (May 19, 2021)

HumbleHomeCook said:


> "Powder metallurgy" doesn't really have any bearing on the sharpening discussion. That is just a method of producing the alloy that results in very fine grain structure. Hardness is also only an indicator and only tells us just so much.
> 
> It's the alloy content that is predominantly relevant, specifically the type of carbides formed in the steel. For example, BD1N and Ginsan are PM steels and both are easy to sharpen. ZDP-189 gets it's hardness from extremely high levels of chromium carbides. These carbides can be abraded by silicon carbide and aluminum oxide. Vanadium carbides cannot and require diamond/CBN. It's physics. Below about 4% vanadium carbide content, there isn't really enough and they are often small enough, to not have that big of an impact so you can get away with SiC or AlO. But beyond that, and once moving past about 600 grit, you need something harder than the carbides to abrade them.




Bingo, not the PM or the hardness HRC.

Some corrections.

BD1N is not a PM steel. It is basically gin1 with Nitrogen added through "blow by" over the melt and the chromium helping pull the nitrogen in.

ZDP-189 gets it's hardness from more carbon in solution, not just the carbide volume.

Good post as always.

I'll add that while hardness HRC isn't as important as the carbide type and volume there is an interesting effect that if the HRC is higher in a steel that has =/<~4% MC it will be significantly more glassy on softer alumina stones even at lower grit.


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## HumbleHomeCook (May 19, 2021)

Deadboxhero said:


> Bingo, not the PM or the hardness HRC.
> 
> Some corrections.
> 
> ...



Thanks Shawn. I honestly thought that BD1N was atomized with nitrogen into powder form and then sintered. Thanks for keeping me straight.


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## Deadboxhero (May 19, 2021)

HumbleHomeCook said:


> Thanks Shawn. I honestly thought that BD1N was atomized with nitrogen into powder form and then sintered. Thanks for keeping me straight.



Yea,there's a lot of them to keep track of.

I first learned about the "blow by" method from a Buderus Metallurgist PhD T. Reip
At a presentation he did at Bladeshow West 2018 for Nitro V.

BD1N. Nitro V, Nitrocut (1.4116N) and a few others get there Nitrogen from this method (~0.10%w N)

Some cast steels are special like N360 and Lc200n that get a pressurized melt(PESR) to force more nitrogen in (=/<0.5%w N) which is significant.

The Nitrided PM steels are Vanax, (35,37,75)
Vancron,(40) Nitrobe 77
(>1.00%w N)

These are extremely expensive steels due to that fancy step added to Nitrided the powder in a vacuum before HIP, cutting to billets and rolling.



There are also other methods to get the nitrogen in the steel but these are less discussed.

For instance, CPM MagnaCut has more Nitrogen than BD1N and H1.


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## Deadboxhero (May 19, 2021)

SolidSnake03 said:


> Depends on what you are looking for in terms of splash and go vs soaker vs diamond. After a boat load of trial and error I’ve found that diamonds leave the best edges on my pm steel knives. By best I mean longest lasting, toothy, cleanly apexed and do that job fast and efficiently. That said all my recommendations below have worked fine on pm steels.
> 
> Also if you have the $$ there is nothing like the Super Vitrified Diamond stones. Very expensive but stunning performance, absolutely the best cutting thing I’ve used regardless of price and eat Maxamet like nothing else short of a full on grinder.
> 
> ...


Super Vitrified, splash and go
Vitrified, not splash and go


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## SolidSnake03 (May 19, 2021)

Appreciate the clarification of that! Yup the Practical Sharpening one's for example are not splash and go I believe but are vitrified. I think that's it because when contacted about those the maker will indicate that those are not entirely splash and go and need a quick soak I believe


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## HSC /// Knives (May 20, 2021)

Deadboxhero said:


> Harbeer, Are you finishing with a diamond loaded leather strop at all?


Not diamond loaded. I use the Tormek PA-70 honing compound


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## Barmoley (May 20, 2021)

SolidSnake03 said:


> Appreciate the clarification of that! Yup the Practical Sharpening one's for example are not splash and go I believe but are vitrified. I think that's it because when contacted about those the maker will indicate that those are not entirely splash and go and need a quick soak I believe


maybe @M-S-T can clarify, since there are a few types, softer and harder. The ones I have 400, 2k, 6k don't absorb any water basically, so I would call them splash and go. Or more correctly they absorb very little. Less than what is usually considered splash and go.


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## Deadboxhero (May 20, 2021)

HSC /// Knives said:


> Not diamond loaded. I use the Tormek PA-70 honing compound


My recommendation, just use diamond spray compound for best results.


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## Bolek (May 20, 2021)

Barmoley said:


> maybe @M-S-T can clarify, since there are a few types, softer and harder. The ones I have 400, 2k, 6k don't absorb any water basically, so I would call them splash and go. Or more correctly they absorb very little. Less than what is usually considered splash and go.


My 6k absorbe much more water than the 2k.


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## inferno (May 21, 2021)

so HSC have you decided on anything yet?


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## iandustries (May 21, 2021)

SolidSnake03 said:


> Depends on what you are looking for in terms of splash and go vs soaker vs diamond. After a boat load of trial and error I’ve found that diamonds leave the best edges on my pm steel knives. By best I mean longest lasting, toothy, cleanly apexed and do that job fast and efficiently. That said all my recommendations below have worked fine on pm steels.
> 
> Also if you have the $$ there is nothing like the Super Vitrified Diamond stones. Very expensive but stunning performance, absolutely the best cutting thing I’ve used regardless of price and eat Maxamet like nothing else short of a full on grinder.
> 
> ...



any downsides to using a diamond plate, and if you had to pick one to use together with an existing naniwa pro 800/3000 setup, which would you recommend?


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## HSC /// Knives (May 21, 2021)

inferno said:


> so HSC have you decided on anything yet?


I guess I have. I’m likely to go with naniwa 1000 grit diamond that’s available here in the EU/France and a Shapton 2000 or 3000

Harbeer


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## inferno (May 21, 2021)

nickel plated diamond plates such as dmt/atoma/all the cheap crap from china feels like crap to sharpen on compared to regular stones.
thats one downside.


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## inferno (May 21, 2021)

HSC /// Knives said:


> I guess I have. I’m likely to go with a 1000 grit diamond that’s available here in the EU/France and a Shapton 2000 or 3000



the 3k is really nice. it my absolute favorite shapton glass. 
it gets really sharp. not as sharp as the 4k which get things scary sharp.
but its much faster than the 4k. 
and it clogs a lot slower.
seems to a be a very good finishing point for stainless and other high alloyed stuff.
but i wouldn't exactly cry my eyes out if i was forced to use the 3k as my only finisher on all my carbon blades.

the 2k pro is also very nice for sharpening lower quality/softer knives that dont really benefit from any higher grit anyway.


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## M1k3 (May 21, 2021)

HSC /// Knives said:


> I guess I have. I’m likely to go with naniwa 1000 grit diamond that’s available here in the EU/France and a Shapton 2000 or 3000
> 
> Harbeer


A single Venev Phoenix stone is cheaper and comes with 2 grits. It might even still be cheaper after shipping and taxes from Gritomatic.


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## SolidSnake03 (May 22, 2021)

iandustries said:


> any downsides to using a diamond plate, and if you had to pick one to use together with an existing naniwa pro 800/3000 setup, which would you recommend?




No real downsides but the feeling of them and that there is no mud/swarf so wide bevels don’t look too pretty after using them unless they are already flattened.

So I run the 240/400 and 800/1200 plates for my full set up. It’s What Gritomatic recommended as a 2 plate set up to cover everything. In your case the 240/400 may be nice to get a good burr going fast on tough steel. The 240 is really fast cutting and no need for anything lower unless doing heavy metal removal

Agree with M on the Venev for you HSC, get one of the Phoenix with 2 grits for less. I’ve owned the Naniwa and they are nice but over priced compared to Venev


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## HSC /// Knives (May 22, 2021)

I appreciate all the responses and the wealth of information provided


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