# Sharpening HRC 65+



## Tristam Douglas (Jun 24, 2019)

I am in need of a few new stones. My old Naniwa trads are on there last legs. That was not a huge issue as I had a huge 7x24cm coti that was a £10 antique fair bargain about 15 years ago. I loved that stone. I left it out on the draining rack and while I was out it met a fateful end. Wife dropped it on the kitchen floor and it shattered like safety glass.

I really want to optimise any new set up towards my Denka/s. Just want to get a decent 1 and 3k atm.

I was doing a bit of research on the Shapton stones when I came across the following article that explained that the different grits are formulated for specific steels. (Apologies if this has been posted before.)

https://jendeindustries.wpcomstagin...oduction-to-the-shapton-pro-and-glass-series/

Has anyone got hands on experience with the range of the shapton Gita and different steels? Ie is the information good?

Should shapton be at the top of the list? The JNS stones sound great but seem to be always out of stock.


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## lemeneid (Jun 24, 2019)

Denkas though hard, sharpen up buttery smooth. You can use about any stone to sharpen Denkas.

With regards to Shapton Pro, they're fairly hard splash and go stones but cut really nicely. I use a 1k shapton Pro for all my knives (all carbon), then proceed on to Jnats. With an Aizu or an Aoto in my next progression. 

You could stop here but TFs and honyakis are the only knives I have that I take to much higher degree of finish though, they're the only knives I have so far that can take and hold that stupidly sharp edge for long durations but thats what makes them so fun to use. If you want to have more fun with TFs, you could buy a couple of higher grit finishers beyond 3k and have fun


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## Knife2meatu (Jun 24, 2019)

Tristam Douglas said:


> [...]
> 
> I was doing a bit of research on the Shapton stones when I came across the following article that explained that the different grits are formulated for specific steels. (Apologies if this has been posted before.)
> 
> https://jendeindustries.wpcomstagin...oduction-to-the-shapton-pro-and-glass-series/



Those statements from that distributor of Shapton's stones is squarely contradicted by Shapton's own guidance on their stones. If you read through Shapton's FAQ and examine the chart Shapton made to guide customers on which stones to use for what alloys/blade-types, you will find that Shapton's own advice is at odds with what the guy behind Jende Industries says.

If you you have a hard time finding the chart, it's at fine-tools.com, I've linked to it in previous comments if you care to look through that to find it.

I have Kuromaku stones, except for the 30k; I don't see that the 320 and 1.5k are particularly different from what one would extrapolate from using the other stones. I do think the 220 is friable to the point of being wasteful if used on easier to grind stock than hardened HSS or other high-alloy; it just melts away on most things. I used to think the 120 wore fast; but compared to the 220, I think the 120 > 320 combo is actually much more efficient for most steel I've put to it.


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## refcast (Jun 24, 2019)

I agree with the denkas. They sharpened up easier than a lot of lower hardness knives for me.


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## ojisan (Jun 24, 2019)

Shapton Pro is just great and I love my Shapton stones. Especially 1000 and 2000 are awesome. I agree 220 is melty, not "hard" at all (but cuts fairly fast). 120 is much harder.

You can ignore the statement in the page, I think it's just misleading. Shapton does have a table for recommend grids for different types of knives/tools. However I've never seen Shapton officially says "XXX grid is formulated for stainless/carbon".


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## panda (Jun 24, 2019)

get the diamond 1k and 6k from jki


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## Tristam Douglas (Jun 25, 2019)

Thanks for the input guys!

Found the info re Shapton’s advice. The Jende article seemed to fly in the face of accepted wisdom. I wondered if there was some little known magic voodoo.

Any opinions on the JNS synthetic vs Nat equivalents? The JNS aoto are mixed grit but I presume the abrasives are uniformly distributed and the stone is uniform in softness etc? Are the figures quoted for a multiplicity of grits spanning the range quoted or a blend of the high and low values?

I know very little about j nats so I will now be digesting the noob guides before I ask for any more input. Having said that what is a fair price for a good aoto if I prioritise quality over size?


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## SilverSwarfer (Jul 15, 2019)

Tristam Douglas said:


> Thanks for the input guys!
> 
> Found the info re Shapton’s advice. The Jende article seemed to fly in the face of accepted wisdom. I wondered if there was some little known magic voodoo.
> 
> ...



I have the JNS Red Aoto. It's a big (thick) muddy stone of mixed grit. Benefits slightly from soaking but unlike other splash-go stones, water/mud management is very important. It's a relatively slow cutter IME for the steel I've used so far. It feels really nice: hard yet muddy, feels slick/smooth (pleasant) and it works very thirsty though it absorbs very little. Feedback is precise when the mud is runny. It tends to get "grabby" or sticky if you move fast and use high pressure when it's getting dry. As expected with muddy stones, it's pretty quick to dish. I keep my Atoma plate nearby and lap often. Finish is on the coarse side of medium. JNS says 2-4k grit range in the mix and the scratches show on your cladding clearly. The rough(ish) finish given is still somehow aesthetically pleasing though. Bright silver finish with visible scratches that still shows contrast (less scratches on ha).

JKI has a Jinzo Aoto that gives similar results, but much different stone. It's a soaker that's muddy and dishes really fast. Audio feedback is much more pronounced than the Red Aoto. Tactile feedback- Jinzo gives much more resistance while the Red feels slick and smooth (for the work it's doing). The Jinzo cuts much faster and gives a more grey finish on your jigane. Big contrast. More expensive, shorter life, but still an interesting and really fun stone.

Also have a Natsuya from JNS. It's phenomenal. It cuts nicely once your water management is balanced. Tactile feedback is a little muted for a hard stone, audio feedback is superb- it's my favorite stone to hear- subtle changes of input are reflected via audio. Any shaping work takes some time investment, but the finish is perfect to segue into a Suita or similar. Slow slow to dish. True splash-go. JNS says "starts about 800 grit," IME finishes are more like 1.5-2k+ depending on pressure and steel. Strangely, during sharpening it seems like you can do some burnishing with this stone -as it gets loaded with swarf and dry- if you lighten pressure.


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## HRC_64 (Jul 15, 2019)

What you need special stones for it stainless steels (Cr Carbides), PM steels (>15% carbides), and especially steels with W and V carbides.
I'm not sure any of the Hitatchi Carbon steels (no matter how hard) have enough alloying ingredients to really require special stones.

However, if you want stones that will do stinaless and PM steels (buy once cry once), look to at least the 2nd generation of synthetics

- chosera
- shapton pro/glass
- king hyper
- JKI or JNS house stones (ask)
- JKI Diamond Stones

If you want something that will deal with the hardest carbides 
(most of KKF avoids these, but they are used in hunting/outdoor knives alot)

- Various CBN and Diamond sprays for polishing


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## HRC_64 (Jul 15, 2019)

There are some good comments on abrasive selection in Larrin's latest article from earlier today
>https://knifesteelnerds.com/2019/07/15/carbide-types-in-knife-steels/


> Abrasives vs Carbides
> Carbide size and hardness is also significant when it comes to grinding and sharpening knives. If the abrasive is softer than the carbide the abrasive is not able to abrade the carbide. Notably, aluminum oxide (Alumina), the most common abrasive, is softer than VC, NbC, and WC. However, if the abrasive size is larger than the carbide size then the abrasive is able to pull out the steel and the carbides together so that the carbide hardness isn’t as important. Abrasive wear tests of S90V and D2 showed superior wear resistance of D2 [7] even though the S90V has a large amount of hard vanadium carbide because D2 has very large carbides. This means that grindability of powder metallurgy steels is better than conventionally produced steels. So grinding and sharpening with coarse grits are generally effective with vanadium-alloyed powder metallurgy steels even if the abrasive is softer. At finer grits the hardness of the carbide becomes more important and polishing vanadium-containing steels can be challenging because aluminum oxide is too soft. Silicon carbide has a similar hardness to those hard carbides but is not clearly harder, and in general silicon carbide is not as good at cutting steel as aluminum oxide. CBN and diamond are significantly harder than any of the carbides so they are generally better at least in terms of grinding and polishing high wear resistance steels with hard carbides.


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## Huntdad (Jul 16, 2019)

HRC thaks for posting that link.


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## inferno (Jul 18, 2019)

Tristam Douglas said:


> I am in need of a few new stones. My old Naniwa trads are on there last legs. That was not a huge issue as I had a huge 7x24cm coti that was a £10 antique fair bargain about 15 years ago. I loved that stone. I left it out on the draining rack and while I was out it met a fateful end. Wife dropped it on the kitchen floor and it shattered like safety glass.
> 
> I really want to optimise any new set up towards my Denka/s. Just want to get a decent 1 and 3k atm.
> 
> ...



did you get any stones yet?

for 1k stones i think glass1k, pro1k, naniwa pro/chosera 800/1k are very good. all these are splash and go, and the glass is the most splash and go. 
for soakers i think the naniwa hibiki and king hyper 1k (hard) is good. 

for 3k look into the glass3k, i think this is one of the best stones they make. fast, good, easy to use, slow to dish and makes a killer edge. *And i think this the upper level for sub 60hrc SS. *and also a very good all round stopping point.

the naniwa pro 2k is a also a very good 3k. but its much more of a hassle to use though since its release abrasive and is much more thirsty, and takes a lot longer to dry. the 2k finishes at around 3k since the abrasive breaks down and get finer on the stone.


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