Thread: grit, grade, mesh, micron & finish

I have seen the comparison chart posted here, on ameritech, two from Pam, on sharpening supplies, and some random lapidary and microfinishing sites - I have been wondering about this because the Norton 4K/8K seems pretty popular, and also because of the usage of the EE DMT hones. These stones use mesh grading, not grit, so are they comparable to JIS grit in the finish created? Norton 4K is 6 micron, because the US mesh grade of 4000 is a 6 micron mesh. But, new Japanese Industrial Standard (JIS) - that it seems most Japanese waterstones use, puts 6 micron as somewhere in the range of 2500, and 4000 grit is 3 micron. Likewise, 8000 mesh is 3 micron, and 8K JIS is 1.2 micron. Both Norton and DMT have an 8K stone, but neither is 8K grit, they are 8K mesh.

It seems that some people think that the stones are assigned certain numbers because the abrasive breaks down, or is a certain shape that gives a certain finish. But to me the numbers advertised just aren't the same scale, or even trying to approximate each other. Like, maybe DMT didn't say, 'hey, this 3 micron plate gives a finish like an 1.84 micron glasstone, coticule with slurry, 1.2 micron King, etc.' They just used US mesh grade and not 'grit'. I am guessing this is the same thing Norton did... but if this is the case, is anyone getting near/shaving edges off a 4K/3 micron abrasive of another manufacturer?

Also, does anyone try to get a shaving edge from 2000 grit sandpaper? On the US CAMI scale, that is 1 micron, around 8K JIS. Or F1500 FEPA from Europe? And is 0.5 micron chromium oxide or diamond generally referred to as 30,000 or 60,000 (mesh)?

Well, there is always the micron rating which is somewhat less ambiguous. There are so many factors that at some point one must rely on actual observed performance rather than manufaturer's hype.

Did you see Bart's thread referenceing an interview with a tech rep from DMT? It discusses some of the things you mention here.
http://straightrazorpalace.com/hones...formation.html

Yeah, I had read that, and it is actually another reason I ask. With the diamonds of the fine embedded about 60-70% of their size is the same true for the EE? If so, the 3 micron diamonds would have about 1 micron exposed. Does that mean they act more like a 1 micron abrasive, about 8k JIS, or is the bonding of waterstones keeping it relatively finer still? Of course, monocrystalline diamond is kinda rectangular & very hard and makes a harsher edge to comparably sized abrasives of many other types anyway.

Also, his comment on controlling pressure applies to any hone that can handle it without being damaged. I do wonder why they don't have a ~12 micron & ~6 micron plate to go between the F & EE. Though I personally am not opposed to going by 1/3 instead of 1/2 for progression, particularly with the speed of diamond.

I have thought about this quite a bit also, and have also read the info from Bart about the DMTs...

With the grit comparison sheet that I cobbled together from info lots of people helped find, I was hoping to clear some of this up....alas is it much more complicated than it looks!

Take the 0.5 micron size diamond for example, people complain about getting a rough shave from diamond that is half that size (0.25 micron), most likely because of it's shape and hardness....if it's CrO, some people have used the 3 micron size and gotten beautiful shaves, probably because the particles are softer and more round.....if it's Cerium Oxide, I believe I read where someone had tried "400 grit" Cerium Oxide and got a decent shave from it, probably because it's so soft and maybe because of it's particle shape (which I don't know), or maybe because it broke down into smaller pieces or something.....

Another example of this was in the thread I first posted the grit comparison in, Glenn compared using a Norton 8K and a Shapton Glass 4K Here ....he didn't say much about it, but I would assume by his reply, that he thought the norton was a smoother edge....

I expect that the Norton 8K gives a smoother edge than the Shapton GS 4K...now whether this is because of the 0.68 micron larger particle size listed by their manufacturers, the binder they each use, the height that each particle protrudes above the binder, the hardness of the abrasive material each uses, the shape of their respective abrasives, or some other factor I never even though of.....who knows....

I would love an answer to these very questions you have asked, but unless someone devotes the rest of their life and an untold fortune in equipment, I don't exactly expect any real answers that we can take as fact.

Well, the DMT EE 8k is comparable to a Naniwa 3k in finish. Other 8k stones seem to be finer than the DMT, but then again the Japanese rating system is different. I don't even know how they come up with the numbers.

Originally Posted by Smokintbird

Another example of this was in the thread I first posted the grit comparison in, Glenn compared using a Norton 8K and a Shapton Glass 4K Here ....he didn't say much about it, but I would assume by his reply, that he thought the norton was a smoother edge....

That post is an excellent example of what is puzzling. On the surface, I can see how it is easily confusing to think one 8K is rougher, beyond acceptable variability, than another 8K. 8K should be 8K. But, 8K what? Is it as confusing to say this 3 is coarser than this 1.84 (now using same scale, microns)? Or, is it more confusing to say this 8K is the same as this F2000 (different scales, same size particles)? Can you shave off of all 8K edges? Is the 8K DMT an acceptable stopping point? If not, is 1 micron diamond lapping film? If you can shave off a 12K, can you shave off a 2K? 2K CAMI is a little finer than 12K Glasstone, and is 1 micron average size like the lapping film.

Obviously, you can't look at just numbers without reference to determine where stones should fit. I personally feel micron rating trumps all other scales because it is more easily understood, and no country, consortium, or company is going to make up their own micron the way a new mesh or grit grading system can be. If the micron changes, it will change for everyone.

Now once you get some idea of particle size, you need to look at the other properties. Well, unless you have HAD, then you just buy them all anyway. Otherwise, all things mus be weighed. If someone said they had a natural Japanese stone that operated over a short range of finishes by creating a slurry or using with plain water, that information alone is as useful as saying you have another stone that is 3K. 3K what?

Oh, and that natural wasn't a Karasu that could provide finishes on the order of 6K to 10K Naniwa, it was an Iyoto that worked more like 500 to 1000. Dang.

edit: I'd also like to throw the ceramics and Arkansas stones out there. Sal Glesser said the different grade ceramics are all the same particle size, but the stones give different finishes. The ultra fine is fine, just surface ground. The medium can eventually wear out, while he says the fine & UF should not. IIRC, Arkansas are similar, the diatoms were all about the same size (3-5 micron), but the different novaculite stones perform based on other factors that determined the density of these little fellers. Stranger still, a hard black or translucent are said by some to create a shaving edge, while no charts I have seen on the web grades them any finer than around 2-4K

Here comes the confusion again????

Guys please don't put words in my mouth I can speak (or type) for myself...

Here is my stance:
You are confusing people to death with the different grit comparisons period end of story...

a Norton 8k you can shave off of
a Shapton GS 8k you can shave off of
a Naniwa SS 8k you can shave off of
a Naniwa Chorsea 10k you can shave off of
a Yellow coticule you can shave off of
a very fine translucent Arkansas you can shave off of
almost all the Japanese natural stones you can shave off of
the Charlney Forest you can shave off of
the BBW Bart proved you can shave off of
a SpyderCo UF you can shave off of
a DMT 8k some people say you can shave off of (I haven't done it)
you can shave off of just about every Barber's hone ever made...

I am quite sure there are more I am missing...

Soooooo that is my stance, when it comes to analyzing your scratch patterns, and trying to put things in order that's great, BUT when it comes to shaving, all the scratch patterns/ grit comparisons in the world don't seem to mean a thing.....

I am sorry that you think I was being negative in all those previous threads, but what I saw was a ton of very mis-leading information that would lead to new people buying way more stones than they need, and actually wrecking their honing by adding un-needed stones, that the charts show should go in sequence....

This of course is JMHO

Originally Posted by hardheart

Stranger still, a hard black or translucent are said by some to create a shaving edge, while no charts I have seen on the web grades them any finer than around 2-4K

Under the US grit rating, that sounds about right. A translucent Arkansas is quite fine, it's estimated to be 8k JIS grit on our wiki, which agrees with my experience. Used dry, it's more like a ~10k stone (JIS rating).

Originally Posted by matt321

There are so many factors that at some point one must rely on actual observed performance rather than manufaturer's hype.

+1 ... that is all you can do and come to your own conclusion on what works for you IMO.

I do really like the try a stone and see what happens methodology.

Personally, all those charts confuse my simple mind.

You guys have fun with them though.

Still working on a bbw shave, but not something I find will work every time for me anyway......

Lynn