Thread: Norton 8k = ~5k JIS?

Originally Posted by Utopian

NO natural stone EVER should be assigned a grit rating. The absurdity of the con artists selling various grits of Chinese hones and ILR hones just proves that they have no credibility at all. They are basing those ratings on scratch pattern comparisons with those of synthetic hones; but as you have noticed, there is a possibility that the grit ratings of synthetic hones may not be comparable so then the question is simple. To which synthetic hone are they making their comparison? The answer is easy, whichever one makes them seem to be of a higher grit.

Don't trust anyone who assigns a grit rating to a natural hone.

I agree entirely, but natural stones are routinely given as various xk in user honing discussions, apart from the claims of sellers. And then there are the various synth claims, to return to my initial question.

Well, regarding synthetics, this is why it is a lot easier to stick with a single line of hones. If you mix and match among various lines, you may effectively move backward in a progression from one hone to the next.

The old standby naturals, such as coticules, thuringians, arks, and so many others that have been around for a long time, never have an assigned grit rating. The two offenders that I mentioned are the ones that I most often notice as being given a grit rating. There have been a few other new on the scene hones that also have been assigned grit ratings. As far as I'm concerned, none have any credibility.

Originally Posted by Utopian

Well, regarding synthetics, this is why it is a lot easier to stick with a single line of hones. If you mix and match among various lines, you may effectively move backward in a progression from one hone to the next.

The old standby naturals, such as coticules, thuringians, arks, and so many others that have been around for a long time, never have an assigned grit rating. The two offenders that I mentioned are the ones that I most often notice as being given a grit rating. There have been a few other new on the scene hones that also have been assigned grit ratings. As far as I'm concerned, none have any credibility.

Again, I am in agreement with you here. It is desirable to stay in-house as much as possible, as far as synth or other reliable company-branded stones (including natural progressions) are concerned.

Originally Posted by gssixgun

There is an old thread in the archives that the author went through the trouble of contacting Norton to find that it is an 8k JIS

I have dug it out multiple times over the last ten years, nearly every time this same question comes up have fun with your search..

PS: You will get tons of response that what you posted is the truth because it has been parroted from the Grit conversion tables nearly a million times

Hone and Shave off a King 6k
do the same off a Naniwa SS 8k
do the same on the Norton 8k

Then tell me your opinion

Interesting. I thought Norton was either using the US grit scale or their own proprietary thing. Never would've guessed they were working off the JIS, but it makes sense considering their largest competitors in the water stone market are Japanese...they'd want to be on the same relative scale as King, Naniwa, etc.

Originally Posted by Marshal

Interesting. I thought Norton was either using the US grit scale or their own proprietary thing. Never would've guessed they were working off the JIS, but it makes sense considering their largest competitors in the water stone market are Japanese...they'd want to be on the same relative scale as King, Naniwa, etc.

I guess

At this point in time I just don't really care any longer, the question has been on SRP for over 10 years AFAIK only one person ever took the time to contact Norton..

If you read my posts it is always the same

Grit is but one measure, it only means the the Norton 8k is a higher grit then the Norton 4k any other comparison is a matter of the user's opinion nothing more

You can't even compare a Naniwa Pro 5k to a Naniwa SS 5k "Accurately" so to me the Conversion charts are a "Best Guess" at their most value, and a "Complete Joke" at their worst

Not even going add to what Ron already pointed out very well when it comes to people "Rating Naturals"

True enough. I just never cared enough to question - or even think about - the misinformation I was working with. Even if the yellow brick was '5K JIS equivalent' the shave off of it is good enough, and it gets me where I want to be before skipping over to whatever finisher I'm planning to use.

Besides, I spend so much time playing with naturals and looking at edges under a loupe grit rating is becoming immaterial. More interested in what my hands can produce and what I see under the loupe than what grit the stone is rated and by who's standard. And of course the results of the shave test, which is more important than any number one can assign to any rock be it made by man or nature.

Originally Posted by Marshal

Interesting. I thought Norton was either using the US grit scale or their own proprietary thing. Never would've guessed they were working off the JIS, but it makes sense considering their largest competitors in the water stone market are Japanese...they'd want to be on the same relative scale as King, Naniwa, etc.

In their 2015 catalogue, Norton lists their water-stones under a JIS heading, leading one to conclude that "Norton 8000" would indeed be equivalent to 8k JIS. From that, one might easily conclude that the allegations that the Norton line runs a little bit coarser are incorrect. However, the only scale that is completely listed there by way of comparison is given in microns; so all that one can say from this is that Norton says its 8000 water-stone is equivalent to 3 microns. From there one then has to seek what 3 microns equates to on a JIS rating, and opinions can vary there. For example, I have a chart from a book that lists 3 microns as 6k JIS, while another chart might say that 3 microns is equivalent to 4k JIS, and another company might list 4k JIS as 3.68 microns and 8k JIS as 1.84 microns, etc. How to account for such discrepancies? Different binders, perhaps, as mentioned?

If someone says, "I got a pretty good shaving edge off 8k," what does this mean--Norton 8000? 8k JIS? a natural stone rated similarly? There is no default rating in such instances from what I can tell, apart from JIS, which may or may not differ from Norton's. In the end, a sharpening stone--or a dedicated set or series of sharpening stones in the case of synths--has its own inherent properties which need to be figured out according to their own terms; and this is why I agree that it is best to stay with the same line of synth stones when possible. Natural stones, on the other hand, are sort of a rating system to themselves, and yet these are often rated as a basis of comparison: "This Jnat leaves a 15k finish" and so on. Again, what rating scale is being referred to here--JIS? Or let's take a commonly recommended honing progression: 1k Chosera > Norton 4000 > Norton 8000 > Naniwa 12k SS. In using such a progression, one might easily think that one is moving from 1k to 4k to 8k to 12k following the JIS rating taken as a default; but since one is dealing stones from two companies, Naniwa and Norton, such stone ratings are keyed differently as to variances in production. Not that such a series doesn't prove effective (apparently it does from various testimonies); it's just to be aware that the assumed progression may not be 1k > 4k > 8k > 12k taken exactly or ideally.

If you look at the chart in that Norton catalogue, you'll find a lot of things aren't as they seem. Notice the hard Translucent Arkansas rated at 6 microns between the 4K and 8K? Think anyone would shave with a Translucent Arkie as their finisher if that were accurate?

Also take a look at Swaty barber hones. Their abrasive is a 20 micron grit - 600 grit equivalent. But anyone that owns one will tell you they polish the edge as well as or better than their 8K hone. The reason this works is because of the very hard binder, the fact that the hones do not release slurry, and the abrasive material being lapped nearly flush with the surface of the stone.

So, Norton uses 3 micron grit in their 8K hone. Are you honing with loose 3 micron grit, or are you honing with grit stuck in a binder that's poking up %50 or less?

Like Utopian said, there's more to the hone equation than raw grit material. If JIS 4k equivalent was a good shave, instead of recommending the Norton 4/8 or Naniwa 3/8 as a first stone, we'd tell all the newbies to grab a King 1/6 and be happy. I only know of one person that uses that as his one and only razor hone. I know of no one that would be happy with a Shapton 4k or Naniwa 5K.

Yes, I have noted that Norton lists its hard translucent Arkansas as being equivalent to their 4000 water-stone, so things may not be as they seem, as you say. And this brings me back to the question of whether or not the Norton water-stone line really matches the JIS rating as stated. But you all have brought up an important point about the binder and the relative heights of the abrasive material, as perhaps exemplified by the difference between a coarsely-lapped translucent Arkansas and a finely polished one.

I have used a Suehiro 1k/6k combo in the past. Off leather, the shave isn't all that bad, but it certainly improves after stropping on red-pasted linen. I imagine that the Suehiro 6k would be fairly similar to shaving off of a Norton 8000, but I haven't tried the latter. One difference might be that the jump from 1k to 6k JIS would be longer than the jump from Norton 4000 to Norton 8000, thereby affecting things in comparison.

What I was originally trying to ask was if someone had compared a Norton 8000 edge to a 5k, 6k, or 8k JIS synth edge and could vouch for the Norton 8000 indeed being similar to an 8k JIS synth. JimmyHAD has sought to address this to some extent, and I thank him for it.

Originally Posted by Brontosaurus

One difference might be that the jump from 1k to 6k JIS would be longer than the jump from Norton 4000 to Norton 8000, thereby affecting things in comparison.

The jump from 1k to 6k is greater than the jump from 4k to 8k. 4k grit is one fourth the size of 1k grit, while 8k is only half the size of 4k.