Thread: Honyama Awase Toishi

Murph and Bigspendur both have points to make here.

The mining of the natural stones is coming to a close. Even togishi, the sword polishers, now use man made stones for most of the base process and finish the blades with the expensive natural stones. The natural stones are good ones, but they are becoming scarce and that is what drives up the price. My advice is to buy them now if you want them.

About blue steel. Mostly manufactured in the Hitachi steel mill. A very good steel, but not handmade. Maybe the knife maker forged it to shape, but I highly doubt that this is anything more than the blue steel found very commonly in high dollar knives in Japan. It is a very nice knife by the way.

Tamahagane, of which I am very familiar, is not higher than 1.6% carbon as smelted. That number is reduced by the time the sword smith has finished his part of the blade. That reduction in carbon content would also be reduced by a tool smith (separate guild) IF he was allowed to have any tamahagane to make tools from. Tool smiths are way down at the bottom of the pecking order for steel of this type since the sword smiths get their picks first.

I think a decimal is off somewhere in translation. Wanting it to be so, won't change the facts.

Originally Posted by rgdominguez

The steel that sushi knives are made from is very hard carbon steel. The Shiro-ko or White Steel has about 8% carbon in it and the Ao-ko or blue steel has over 10% carbon in it, much higher than any European steel which have about 1% carbon in them. I think that they would probably tear up the soft European stones. The fascinating thing is that these stones are hard but with a very fine polishing grit, upwards of 12000. I didn't make the connection with razors at first, the obvious is hard to see sometimes! But when an experienced honer I know who has many Belgian and Escher stones in his collection told me that by far he prefers his Honyama Awase Toishi stone to any other hone, the truth dawned on me. I tried it and was amazed at the results!

No steel contains 10% carbon, you are talking out of your hat. Cast iron only contains 4%!

http://www.paragoncode.com/temp/YSS_HCC_spec.pdf

See this file for a breakdown of the carbon percentages in japanese steels. Blue has 1.5% carbon.

Please find a reference for this 10% claim you are making.

I just don't think steel could have over a 10% carbon content. I remember reading about guitar makers trying to make fretwire that had about an 8% nickel content. Nickel is about the same hardness on the Mohs scale as iron. The result was that their machines continually broke down due to the extreme hardness of the metal. I have no idea if steel with 10% carbon content or greater could be made, but it seems there'd be no way to feasibly shape it or machine it.

I think that it's great that this thread has stimulated so much interest and thought. The discussion on the carbon content of the steels employed in making sushi knives, while interesting, does not seem to me central to the original theme which is the performance and romance of sharpening things with natural Japanese stones. I've interacted with several sushi knifemakers who have claimed these high carbon contents. There may be something to the language difficulty thing, there may be a little exageration going on, who knows and who cares! The point is that the Japanese somehow get much more carbon into their steel than the rest of the world. And who says that Japanese Master Forgers are necessarily limited to using commercially available steel? Who says that they can't forge steel with their own "secret formula"? After all, they're Master Forgers, aren't they? And I also doubt that any one of us knows everything about the composition of ALL the steels in the world!

Yes, this is a very good topic.

Well, I know the fellow who runs the smelter in Shimane three times a year to make all the known sword quality steel that is used for nihonto. Akira Kihara. He taught me a thing or two. I'm confident that knowing the source material for their serious (nearly religious affection) handmade steels, no secrets abound waiting to be found. All smiths who are licensed to make swords, must buy their steel from this fellow's operation. It's a law.

That same set of laws also separates those who make steel from those who forge it. So a master forger, may understand how to make the steel, but he is prohibited from doing so.

I agree that any smith could alter the chemical structure of the steel they got, but for the most part, if they did, it would not be the same stuff they started out with. They could not advertise it as that starting material then could they. If one thing is well known about the Japanese, misrepresentation of a product is not one of them.

However, no commercial steels are available with anything even approaching the numbers represented. If commercial industrial processes, with the finest of engineers and metallurgists, are not capable, I can think of no living smith who could.

And, I know a fellow, now living in the US, who is the heir to a Japanese family operation for making agricultural implements and kitchen knives. Murray Carter is his name. He uses an Hitachi blue number one super steel in his kitchen knives as did his teacher, and does not use any secret recipes. If he did use something like that, I seriously doubt he would label the material blue steel as in the ads.

The Chinese were likely making steel at or near the same quality as the Japanese as far back as 2500BC. The handmade smithing/smelting process likely came to Japan via Korea. There are historically extant Korean swords with distinctly Chinese features and homemade steels in them.

Don't leave out the Indians. They were making wootz steels with carbon contents upward of 1.6% long before Japan was even discovered by the west.

I suspect that this is advertising hype or merely an error in translation. Steel is steel, there aren't that many. References are readily available.

Mike Blue, this is excellent information and no doubt points out that my understanding of the carbon content of Japanese White and Blue steel needs adjustment. The things that I have learned from this discussion to date are:

1. Japanese steel for knives and swords has a much higher carbon content and therefore hardness than Western steel used for the same purpose. Japanese Blue Steel has a carbon content of around 3% or about 5X higher than Western steels and Japanese White Steel has a carbon content of around 3% or about 3X that of Western steel.

2. Master forgers must use a certain grade of steel for making swords. (Does this constraint also apply to sushi knives?)

3. Natural Japanese sharpening stones can be successfully used for sharpening razors and have their own set of virtues and benefits. If this is the case for Japanese stones that cost a mere $500.00 imagine what results we would get if we could use one of Master Takeda's $25,000.00 stones!!! I'm hoping that one of our members will buy one of these stones and report back to our forum. Failing that, I will offer my services to study honing with one of these stones. We can take up a collection to buy one and I will gladly volunteer to be the responsible custodian of the stone at no charge!!!

Originally Posted by rgdominguez

Mike Blue, this is excellent information and no doubt points out that my understanding of the carbon content of Japanese White and Blue steel needs adjustment. The things that I have learned from this discussion to date are:

Without trying to embarrass, I want to say that I am very impressed here. This is a fine example of humility and character.

Originally Posted by rgdominguez

But when an experienced honer I know who has many Belgian and Escher stones in his collection told me that by far he prefers his Honyama Awase Toishi stone to any other hone, the truth dawned on me. I tried it and was amazed at the results!

Rich,

I have already sent an inquiry to the guys selling the stone, hopefully they'll get back to me soon. But this thread raises many questions:

So how many razors have you honed on your stone? What brands?

What was the difference with your Eschers? Did you use the softer or harder part of the stone? Or, if both - in what sequence?

Are you saying that your stone is better than all your Eschers and Belgians?

Can I know the name of the honemeister in FL (I am also in FL, might be able to get some lessons from him and he might even let me try his stone on one of my razors?) And what's the final word on whether he prefers it by far for *all* razors above all other hones vs. he only likes it on a *few* razors?

Basically, I am trying to see if I really want one of these puppies.

Thanks
Ivo

I'll try to address these in turn. Hopefully this helps understanding.

Originally Posted by rgdominguez

1. Japanese steel for knives and swords has a much higher carbon content and therefore hardness than Western steel used for the same purpose. Japanese Blue Steel has a carbon content of around 3% or about 5X higher than Western steels and Japanese White Steel has a carbon content of around 3% or about 3X that of Western steel.

Hardness is a value dependent on carbon. Below 0.4% hardness is superficial. Hardness will increase with increased carbon content. But hardness reaches a maximum value at about 1.2% carbon. There is a reason that most modern steel mills stop the carbon content at that point. But that is a matter of economics and practical factory operations. The return on performance is not worth the cost. However, that being said, a steel with a content of 0.8% at a Rockwell hardness of 60 is the same hardness of a steel with a content of 1.2% carbon. There is no functional difference in hardness even though the carbon content is different. At this point, the heat treatment of both steels makes all the difference, not carbon.

Carbon specification for Blue steel is 1.2% plus alloying elements including tungsten, molybdenum, chromium and vanadium. I honestly don't know where these numbers of 3% keep coming from. They could be true if this steel was a CPM steel (crucible particle metallurgy). Blue steel and white steel are not CPM steels.

The Germans, Swiss, Swedes, English and US makers of steel would be a little huffed if all the credit for these steels were given only to the Japanese. Any number of very credible steel mills in European countries, and the US, routinely make steel at or equal to the Japanese every day. Example: German Silver steel can contain up to 1.2% carbon with chromium, vanadium and molybdenum. Hmm, coincidence? not hardly.

For a long time, there has been an unofficial competition between Germany and Japan over who could make the better steel for kitchen knives. If you look at Wostenholm or Global knives, two good examples, you'll find the alloying content so similar that I wonder if they didn't cut a deal to simplify making the steel. There is no winner yet. It falls to subjective feel or judgement about whose knife cuts better.

There is nothing magical about Japanese steels.

2. Master forgers must use a certain grade of steel for making swords. [COLOR=Red](Does this constraint also apply to sushi knives?)

All Japanese swordsmiths must buy their sword steel from a single smelting operation. They are not constrained by the grade of steel produced by that smelter. But the oldest smiths get first pick of the litter as it were and the younger smiths get the lesser quality material. Any swordsmith who makes blades with other material will suffer some issues with the certifying body. It has been tried before. It didn't work. Following the rules is a very important thing in Japan.

Some Japanese knife makers may have access to the steel made at this smelter, but that is highly unusual, and I suspect that they are very old smiths who are also licensed swordsmiths. The possibility that someone outside the group of swordsmiths could have some tamahagane would cause a riot. Now this is not to say that they couldn't hammer an old broken sword into a knife shape....then they would advertise the blade as tamahagane from old swords and not as blue steel.

/COLOR]3. Natural Japanese sharpening stones can be successfully used for sharpening razors and have their own set of virtues and benefits. If this is the case for Japanese stones that cost a mere $500.00 imagine what results we would get if we could use one of Master Takeda's $25,000.00 stones!!!

I admire anyone who can make good use of stones like that. In the end, you have to use the tools you can afford. Then practice, a lot.

I don't think WE could do much with a stone of 25K$ that we couldn't do with a stone that costs 100 times less.
After all, a master polisher has 40 years of 8 hours daily experience under his belt. I have been honing razors for half a year now. Most of us have only a coupe of years, and only occasionally at that. Of course there are excpetions like Lynn, Bill, Joe et al.

And then I suspect that the stone costs so much, simply because it is big and because it is very rare for a stone like that not to be picked up before it leaves japan.

But yes, this thread is great.
To Mike Blue: