Naniwa Diamond Hones

I was looking for a good (flat) diamond hone to use as a bevel setter and perhaps a slurry stone for my high grit naturals. As I already have Naniwa Chosera and really like them I decided to try out one of the Naniwa Diamond hones, I chose #1000. They retail at about 15,000 yen or about $165 USD (using recent rates).

http://www.dogudoraku.com/catalog/im.../p/39261_1.jpg

It arrived in a typical Naniwa box and came with a 'dressing stone'. This was my first indicator of things to come. The honing surface is a real green colour and the green was 1mm thick. I have read that new diamond hones can be harsh so I used the dressing stone on the honing surface, to what end I don't know.

I also went over the surface a few times with an old Mora Knife that I have been slowly restoring the edge on for quite some time.

So I took the hone for its first ride with a straight and after 10 or 20 laps I found under magnification that I wasn't getting equal scratch over the entire bevel. I should have checked for flatness from the start, and this is what I did next. Sure enough a very slight cupping over the entire honing surface (lengthwise).

Well I didn't want to lap it, as there is only 1mm of abbrasive. So I contacted the seller and sent it back and he confirms the problem and has refunded my money. In conjunction he has pointed me to some higher-end diamnod hones made by another Japanese company that are all in the $500 range (here's a link, scroll down to the very bottom of the page). Each one has 3mm thick of abbrasive on the honing face again a diamond ceramic mixture. Even with that thickness I would be hesitant to lap it as the amount of money going down the drain would always be on my mind.

The Naniwa Diamond hone had a great feel, similar to the Chosera but is no longer an option for straights (for me at least). With its thin layer that will most likely need to be lapped I would go with a cheaper option.

ew, that´s awful. DMT´s are way cheaper and completely flat.
I always wondered how these Naniwa Diamonds compared
but was totally shocked by the price.

I didn´t even know these were ceramic bond diamond hones...
makes no sense to me. It´s so simple to produce flat surfaces and coat them with diamond/nickel...

Well thanks for the Review.
Maybe you check out the DMTs or the Atomas recommended by japan-tool.com

DMTs are not 'completely' flat. They are within a certain tolerance that is acceptable for honing or lapping but not as close as a Shapton GDLP. I had a DMTC and a DMTEF that I sent back to the factory because they weren't flat.

They agreed with me on the DMTC but not on the EF. So they replaced the C and returned the EF to me as is. My F is the only DMT plate that equals the GDLP in being flat. All of the others, XX, the returned EF, the replaced C and my 8000 are not absolutely flat. Referring to 8x3 continuous plates. As I stated above although they aren't 'flat' they are good enough to do the job.

Thanks for the review on the Japanese plates Seth. I wouldn't be spending that much on a diamond plate but it is good to know that expensive doesn't necessarily insure perfection.