Thread: Japanese Grit vs. American Grit

Originally Posted by OLD_SCHOOL

Well this is a complete left field guess, but again with my temperature analogy. There is a point I think in the negatives, where Fahrenheit and Celsius are the same. I will also point out that this is from high school memory, which is not exactly fresh anymore so I could be mistaken.

Yeah, but every other stone is the same...#120-white, #220-Moss, #320-Blue/Black, #1000 Orange and so on, up to #30,000-purple....All of them are exactly the same in Japan/US listings, except for the cream.

That would mean that there is only one point where the two scales DON'T coincide. Certainly not impossible, but very odd...

The more I think about this, the more confused I get.

Originally Posted by JimR

It's a mystery...I dropped an email to Naniwa asking why the 12,000 wasn't available in Japan, maybe there' ll be some kind of roundabout explanation. I'll contact Shapton later today...I suppose I should actully do some work at some point.

Good luck with that. I have emailed them several times in both English and Japanese and they have never answered. If you get an reply from one of their reps ask about the colour difference with the pink and blue #10000 Chosera.

Also, the grit confusion could have attributed to listing the micron size on the glass stones to lessen the confusion of mesh grit debates. With the micron sizing everyone is happy....

Originally Posted by OLD_SCHOOL

Perhaps it has something to do with measurements. Like USA still uses imperial measurements and Japan uses metric, and temperatures, Japan uses Celsius and USA uses Fahrenheit. So perhaps whatever Japan uses for measuring their grit size, is different from what USA uses.

Just an idea.

The problem is that you cannot measure the finer grits at all, since a mesh sieve is only so big.
The industry more or less gives a clue (whenever they have a clue).
Their grit size might be an estimation for the US market, depending on the other products available there.
It has nothing to do with ANSI (much smaller numbers), the US measuring system - well and nothing with FEPA either (ours). Those three systems (as well as the old GDR, the one in poland and the russian) are not compatible in any way. Like You can't guess from a FEPA 800, which is roughly a ANSI 1200 or a JIS 3000, a GDR F7 a UDSSR M7 a PM F800 that a FEPA 1200 is this or that, cause the factor for multiplication is different for each index and it is progressive.
FEPA 1200 is about the finest you can determine with a mesh sieve.
So thats where the tables end that my brother dug out of his folder from when he studied that.

Originally Posted by JimR

Here are the some possible explanations I have come up with.
1. They feel that since the American market is bigger, it might be more willing to pay a bit more for the slightly higher grit (unlikely--Japanese tool users are VERY willing to pay high prices for quality...).
2. The Shapton stones are, in fact, identical but there is a difference in grit rating in the US making a Japanese 10,000 equal to an American 12,000; 12,000 to 15,000 etc. (JImmyHAD, who is experienced in these things like I never will be, says they are different.) This would also be unlikely, since the other stones have the same numbers...
3. The Shapton stones are identical, and they're just saying it for some weird reason that we Westerners could never understand. Probably something to do with Ninjas.

I go with number 3. Though none of this explains the Naniwa stones....because they still have a 10,000 in the States, right?

Soooo...what have I missed?

I agree with number three. I don't have any reason, I'll just pick any answer with ninjas in it. All they do is flip out and kill people! They're totally sweet.

Originally Posted by Pete_S

I agree with number three. I don't have any reason, I'll just pick any answer with ninjas in it. All they do is flip out and kill people! They're totally sweet.

People in Binghmpton, NY don't think that behavior is so sweet.

The Pink Chosera is for girls and the blue Chosera is for boys.

So we have resolved one of the issues.

The best site I have found for Hones and Naniwa hones is the following:

Japanese Waterstones: Naniwa

You have to page down to see the hones.

But clearly there is a 12000 grit.

I've just ordered the 800/5000 to complement my Chosera. I'll let you know how it goes but the 800/5000 and the 3000/8000 combo stones represent great value. The price will I think probably rise soon.

Interestingly on the Naniwa Duetschland web site, they don't list the 12000 hone or the combination hones.

Also to add to the confusion, they advertise a Superstone range and a more expensive Superstone + range.

So it gets more confusing.

English they do!

Super-Kombischleifstein Naniwa
Körnung: 3000/8000

Super-Kombischleifstein Körnung 800/5000
Serie Super Stone

Abziehstein Körnung 12000
Serie Super Stone

Olivia,

This is the site I couldn't find the hones on.

Naniwa Deutschland - Super Stone