Thread: Naniwa SS 10k vs. 12k

Originally Posted by Euclid440

If 25 percent of the grit of stone were larger grit than the grit rating of the stone, I would return it.

In FEPA F standard only 3% percent of particles are larger. JIS is not better standard. Hones 10k and finer are not covered by standards.
I have Naniwa, Suehiro, Shapton, King stones and more others.
I started to sharpening 19 years ago.

The “FEPA F Standard”, Oh, why didn’t you say so….

Ok, you win.

Originally Posted by atercz

I wrote about synthetic stones. It is not possible check every abrasive particle in every stone. Read following document: http://www.engis.com/pdf/Particle-Si...s-summer07.pdf, chapter "SPECIFICATIONS FOR PARTICLE SIZE DISTRIBUTION ...".

Syntetic stone is not consistent but much more consistent than natural.

Originally Posted by atercz

Sieves are used for 60um (jap. synt. stone #320) and bigger particles. For smaller particles are used cyclone abrasive separators.
The separators can not completely ruled out larger particles. Factories milling and separation of abrasives are not exactly clean environment. Very pure sized abrazive would be too expensive.
Determination of particle size in the samples is not so simple. The methods used are sieves, sedimentation or computer analysis of microscopic images. Error measurement ranges up to 25%. Not only can not be separated abrasive, but not often to find out exactly how well they are separated.

Deviation of bigger particles is often small for razor sharpening. Eg. JIS #8000 (FEPA F 2000) mean particle size is 1.2um +/-0.3 and up to 3% of particles from 1.5 to 3.5um particles.

I purchased synt. stones with this error because they are cheap and available. Do you have better option?

Originally Posted by atercz

In FEPA F standard only 3% percent of particles are larger. JIS is not better standard. Hones 10k and finer are not covered by standards.
I have Naniwa, Suehiro, Shapton, King stones and more others.
I started to sharpening 19 years ago.

Originally Posted by Euclid440

The “FEPA F Standard”, Oh, why didn’t you say so….

He already did.

<sarcasm on>
+/- 0.3 um? Oh no that will just leave gigantic scratches readily visible in any electron microscope! That might scratch my hair before cutting it!
<sarcasm off>

<rant on>
So I really hate it when people apply the statistic numbers and standards to the wrong thing.
The particle size link (http://www.engis.com/pdf/Particle-Si...s-summer07.pdf) applies to one company's separation technique of CBN and diamond powders which are not used in the Naniwa 10k or 12k. There are other companies that do it differently. So while the link is full of good information it is just useless fluff.

And as stated, hones 10k and finer are not covered by the standards so applying the standards in relationship to a 10k or 12k is just a waste of time.

<rant off>

The 12k naniwa leaves smaller scratches than the 10k. You can look high magnification and see the size difference or even measure the difference of the scratches.

Originally Posted by Utopian

He already did.

Really? Wow?

Wow it looks like I really sparked a big debate type thing! HAha, well I have the 10k, but I went ahead and bought a 12k anyway... figured i'de use it to polish knife bevels as well, so all I have to get next is the 8k SS stone. I have an 8k glass, not sure how similar in micron it is to the SS 8k
The 10k SS is 1.37 micron, does that make the 12k like 1.05 micron? The glass 16k is .95, I considered buying that with my glass 500, 1k, 4k, and 8k instead, but I really like the super stones on razors... gah I have too many water stones. I need to sell some I think. Thanks guys!

If you have an 8K Shapton, you don’t need the 8K Super Stone and it will not make a difference finishing on the 10 or 12k.

But if you are looking for a great 8K, the Naniwa Snow White, the old one, (IF-0001 Junpaku) not the new T-380, is a great 8k stone.

Feels much like a Super Stone but more aggressive and without the loading common with Super Stones. Lays a fine stria pattern and a very straight edge.

I cannot bear to read through all of this (tell me if I am wrong), but the Naniwa 10k has the abrasive finely ground in with the synthetic substrate and is a solid color as are the lower grits.
By comparison, the 12k SS has tiny dark dots all over it's surface. These are the actual abrasive in this hone, as I understand it. As they are harder, the substrate wears around them and they stick up. This is why you lightly lap the 12 SS properly after only a few razors. If you don't, it is a bed of nails, I think.

If you have not lapped your 12k, the 10k would definitely be better!
YMMV

My 12kSS is the pink one, it’s old and nothing like that. Leaves a smooth even stria pattern and super straight edge.

I have use some of the new White ones, and they work pretty much the same to me.

Originally Posted by sharptonn

I cannot bear to read through all of this (tell me if I am wrong), but the Naniwa 10k has the abrasive finely ground in with the synthetic substrate and is a solid color as are the lower grits.
By comparison, the 12k SS has tiny dark dots all over it's surface. These are the actual abrasive in this hone, as I understand it. As they are harder, the substrate wears around them and they stick up. This is why you lightly lap the 12 SS properly after only a few razors. If you don't, it is a bed of nails, I think.

If you have not lapped your 12k, the 10k would definitely be better!
YMMV

I'm not sure I agree. I just shot this photo of the two.