The Aoto? or the Ohira?
And why? I paid little for these, less than 1/2 of what I paid for my coticule.
The hope is that I can set bevels and remove chips in place of my DMT and leave scratches that are not as deep. Most Aoto come from Kouzaki:
from Japan Tool:
Quote:
Kouzaki is situated in the west side of Kyoto. It was famous for its med grit stones called Aoto (Blue stone). Kouzaki Aoto is considered to be the best Aoto, but they are almost impossible to find nowadays. Recently Kouzaki's Suita is starting to receive it's popularity long after this quarry was closed. It suit modern hard steel with the stronger cutting strenght. Suita has the strongest cutting strength of all stratum.
These stones are for Nakato sharpening where you can use either natural or synthetic stones (in the 1000-4000 range). The claim is that the natural stone will leave less deep and softer scratching that will be easier to polish out with higher grade naturals. Boker sells a synthetic Nakato stone at 1000k Amazon.com: Nakato Sharpening Stone: Kitchen & Dining
The Japanese hone masters (can't really call them honemeisters) say this is where they go from sharpening to polishing. Coincidence that we have been talking about the 1000-4000 grit range with this very same idea?
another quote from Japan Tool:
Quote:
Aoto is a natural medium stone you use between #2000 synthetic and #6000/8000 synthetic or natural medium finishing stone. It is possible to jump to #8000 from #2000, but it takes long time to erase the marks from #2000, and also you'd lose a lot of #8000 by fixing the flat of the surface.
Although synthetic finishing stones are fast in cutting thus very convenient for daily use, the marks that's incised are quite deep even with #8000, it takes lots of time to erase it with the finishing stone. So when I want to make the edge extra fine, I would switch to natural stones altogether after #2000, and use Aoto > natural medium finishing stone > natural finishing stone.
This is where Narutaki fits as other Aoto from Kouzaki, Inokura, Miyagawa, and others. Kousaki is just the most famous.
330mate says that these softer stones are used in the first step in the final stage of sharpening and come from:
Quote:
The mine list which produces a lot
Takashimamyoukakusan ,Ohira ,Mizukihara ,Hakka ,Okunomon ,Yaginoshima ,Kouzaki ,
The stratum list which produces a lot
Shallow of Tomae ,Suita ,Namazu ,Softer Renge Suita,AKAPIN ,The stratum that touched air and water for many years ,
Akapin is the shallowest layer mentioned by So at Japan tool and, apparently, they can be found up to the shallower layers of Suita.
The next step up would be to the medium stones where we are moving from sharpening to polishing. (at least this is my interpretation).
Quote:
Medium is suitable for...
- To make most beautiful haze and mist.
- Sharpness lasts for a long time if hardness of steel rise up to Hrc62.
- Accept wide range user with sharpening skill.
- Top class sword finisher which production is very very few.And very expensive.
- 2nd step final stage sharpening which is suitable for Japanese planes ,chisels ,razors.
- Hi-class water quenching Japanese chef knives and blade tools.
This is where I see my Oohira stone fitting in. If It performs as expected.
Quote:
.The mine list which produces a lot
Ohira ,Mizukihara ,Hakka ,Okunomon ,Yaginoshima ,Kouzaki ,Shobu ,Nakayama ,Okudo ,Narutakimukouda ,
The stratum which produces a lot
Suita ,Many kind of Tomae ,Fresh colored Tomae ,Much Tomae in mines which is located in North of Mt.Atago.
Finally we get to the hard stones (like most of us have discussed experimenting with) - Shoubu-dani and Nakayama stones are the only genuine Hon-yama stone, but many of the deeper suita can do the same things. We across the sea can't really handle the stones before buying and we are forced to decide our tolerance for risk.
This is not a effort for the faint of heart.
I am also hoping to get that refinement in grit by lapping a little, honing a little, then lapping some more in order to refine the chert.
Ultimately I don't know my Aoto's pedigree. But it is supposed to fill the gap between 2K and 8K. Properly lapped, it should be what I am looking for.