# Abrasives in Micron Scale: Grand Logarithmic Grit Chart



## Mr.Wizard

[size=+2]Abrasives in Micron Scale: Grand Logarithmic Grit Chart[/size]

I would like to present a new format of grit comparison chart. In the chart I seek to display the information as compactly and intelligibly as possible. Since abrasive particles sizes cover several orders of magnitude a logarithmic scale is most appropriate. A logarithmic scale also has the property of equidistant spacing for any geometric progression, meaning that a theoretically ideal stone series will be uniformly spaced in the chart. Stated another way, two grits that differ by a specific ratio will be a specific distance apart on the vertical axis of the chart whether they are 1.0 and 1.5 micron or 200 and 300 micron.

I must stop and give tribute to Komitadjie's Grand Unified Grit Chart which was my inspiration for creating this one, and after which mine is named in homage. While I expect the charts to be compared they are independent entities. None of the data from Komitadjie's chart was used in the creation of my own except for the BRKT and Spyderco ceramic approximate values which I included for completeness. All other values I sourced elsewhere, though some sources may be common to both.

I spent considerable time assembling this chart therefore I am not releasing it into the public domain. I retain control over its distribution and use as detailed in the README and LICENSE files. I ask that it only be shared by linking to the original source: http://myplace.frontier.com/~mr.wizard/GLGC/

Please see http://myplace.frontier.com/~mr.wizard/GLGC/README.txt for important details about the chart including how to interpret it and what it does and does not represent.

The chart and README will be updated if and when corrections or improvements are appropriate. Previous versions as well as additional charts may be made available in the /GLGC/ directory. 





I am soliciting feedback on the chart presented above. Any corrections and all suggestions are welcome.

Please ask any questions you have regarding the chart and its interpretation. Anything that is unclear shall be additionally explained in the README, and potentially modified in later revisions.

As explained in the README file I chose to limit the range of the chart to keep it compact. A format I considered is to include additional scales to cover the macrogit and submicron ranges. Please see the file "GLGC RC2.png" in the directory linked above. I request feedback on this layout as well.


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## chinacats

Thanks Mr Wizard! 

I believe this would be a good addition as a sticky somewhere for easy reference.

Cheers


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## mark76

Thanks a lot, this is very useful! It must have been a lot of work.

And Jim is right, definately worth a sticky.


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## Dave Martell

One thing I'd like to note is that the very 1st person to ever do a grand unified abrasive chart on any forum was cbwx34 (Curtis). I believe that this all came from his idea and I'd like to see him get some credit for his contribution, even if only here.


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## apicius9

Very nice work, thanks! Just to better understand - what is the norm for ordinary American sandpaper?

Stefan


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## Dave Martell

Where are the stones (abrasives) that we use on Japanese kitchen knives? I ask because there seems to be very little (just Shapton ?? & Naniwa Chosera) here that applies to what the member's here use. There's a LOT missing for this to be of much value to our discussions. 

I'm not trying to poo-poo on your shoes, I can see that you did a lot of work, but this is more aligned for the crowd that relies on guided sharpening devices and the like vs free handing on stones.


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## chinacats

I was under the impression that the JIS category was for "normal" synthetics? That said, I can't seem to enlarge it on my phone to read the categories.

And a big Cheers either way to Curtis fit getting this started.


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## Dave Martell

chinacats said:


> I was under the impression that the JIS category was for "normal" synthetics?




JIS is the Japanese standard but there's more it than that. From what I recall Pam talking about years ago s that there's actually two systems used in Japan to rate grits and from that comes some confusion when talking about or rating abrasives from there. 

If using the chart I see that the Naniwa 10k is rated just above JIS6000? 


The point I was actually referring to above in my previous post is that he's got some maker's info in the chart while leaving out so many others. I would either include them all or leave them all out and stick to the numbers.


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## chinacats

Dave Martell said:


> JIS is the Japanese standard but there's more it than that. From what I recall Pam talking about years ago s that there's actually two systems used in Japan to rate grits and from that comes some confusion when talking about or rating abrasives from there.
> 
> If using the chart I see that the Naniwa 10k is rated just above JIS6000?
> 
> 
> The point I was actually referring to above in my previous post is that he's got some maker's info in the chart while leaving out so many others. I would either include them all or leave them all out and stick to the numbers.



Dave, thanks for the clarification. If there are two basic systems, are they related to composition? Curious how far apart they are by numbers? I guess that is part of why some stones perform so much differently than others, something I hadn't considered but makes perfect sense.

As to the chart, don't know how difficult it would be, but if you could compare just two at the time like on gator's steel site it may eliminate some of the difficulty in reading?

Cheers


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## Dave Martell

Dave Martell said:


> From what I recall Pam talking about years ago s that there's actually two systems used in Japan to rate grits and from that comes some confusion when talking about or rating abrasives from there.




I should have said that there's two systems to measure abrasives, or least there's older and newer standards used in Japan. I don't know the specifics though, I just recall Pam pointing this out, or at least something to that effect.


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## JBroida

knowing what i do about stone companies in Japan, i have reason to doubt quite a few values on there regarding various japanese products. I really wonder where many of the numbers came from.


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## Mr.Wizard

mark76 said:


> Thanks a lot, this is very useful! It must have been a lot of work.



I truly hope it will be useful to a wide audience. It proved to be much more work than I imagined.




Dave Martell said:


> One thing I'd like to note is that the very 1st person to ever do a grand unified abrasive chart on any forum was cbwx34 (Curtis). I believe that this all came from his idea and I'd like to see him get some credit for his contribution, even if only here.



I will note that in the README. Do you have a link to his original?





apicius9 said:


> Very nice work, thanks! Just to better understand - what is the norm for ordinary American sandpaper?



Most likely I belive it will be CAMI. (Coated Abrasive Manufacturers Institute.) Be aware that the standard used may vary within a product line. For example Norton Black Ice waterproof sandpaper is graded in CAMI, JIS, and FEPA-P, depending on the specific product. As noted in the README and described in http://www.uama.org/Abrasives101/101Standards.html there is also apparently an ANSI coated standard ("ANSI B74.18-1996, currently under revision") but despite effort I could not find any free specification for it. (From that page it appears to be close to JIS.) I did not feel like paying for an obsolete technical document. Plausibly the included ANSI standard might be used but it is actually intended for bonded or lose, not coated abrasives.





Dave Martell said:


> Where are the stones (abrasives) that we use on Japanese kitchen knives? I ask because there seems to be very little (just Shapton ?? & Naniwa Chosera) here that applies to what the member's here use. There's a LOT missing for this to be of much value to our discussions.
> 
> I'm not trying to poo-poo on your shoes, I can see that you did a lot of work, but this is more aligned for the crowd that relies on guided sharpening devices and the like vs free handing on stones.



If there is any available standard specified in or readily converted to median micron values I would like to include it. I believe that JIS 1998 is still the official standard for Japanese synthetic stones. However a number of manufacturers have chosen to use a different scale. The Shapton stones specify micron values directly. The Chosera stones are popular (esp. for guided sharpening?) and data for them was available. Also included that you did not mention are the Norton and Sigma Power Select II stones. If you have specific values for any other line of stones I can include them.

Please understand, as detailed in the README, that with rare exception I will not be including values based on approximate or relative performance but only actual particle size distribution. The chart does/can/will not compare absolute abrasive performance between columns.





chinacats said:


> I can't seem to enlarge it on my phone to read the categories.



You should be able to click on the chart in my original post for a direct link to the PNG image itself.





Dave Martell said:


> JIS is the Japanese standard but there's more it than that. From what I recall Pam talking about years ago s that there's actually two systems used in Japan to rate grits and from that comes some confusion when talking about or rating abrasives from there.
> 
> If using the chart I see that the Naniwa 10k is rated just above JIS6000?
> 
> The point I was actually referring to above in my previous post is that he's got some maker's info in the chart while leaving out so many others. I would either include them all or leave them all out and stick to the numbers.



I have only seen one JIS abrasive grading standard. There is more than one revision, e.g. 1987 as well as 1998 but they are too similar to include both as I recall. Again if you have other information I will gladly revise the chart.

Yes, the 10K Chosera just a little finer than the JIS 6000 standard. At least for the Chosera line Naniwa does not use the JIS standard which is a major reason for its inclusion in the chart. 

As a variation I can make a more compact chart that shows only official standards if there is demand. However my impression is that this will be of less use given the number of non-standard products on the market.





chinacats said:


> As to the chart, don't know how difficult it would be, but if you could compare just two at the time like on gator's steel site it may eliminate some of the difficulty in reading?



It is probable that you want to use the chart in a way it is not intended to be used. Please see the README file. Intentionally the chart compares particle distribution numbers, NOT abrasive performance. It is simply not possible to compare abrasive performance with a single number.






JBroida said:


> knowing what i do about stone companies in Japan, i have reason to doubt quite a few values on there regarding various japanese products. I really wonder where many of the numbers came from.



Please be specific. I welcome correction but I cannot work with vague assertions. There are only three specific Japanese lines included. Shapton provides values themselves. The Chosera values come from Clay Allison of Wicked Edge. The Sigma Power Select II values are from a Sigma Power retailer who related values stated by Sigma Power but only for that line. This was from a personal email so I would need permission to further disclose the source.


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## Mr.Wizard

Correction to my earlier statement: "I have only seen one JIS abrasive grading standard." Reviewing my sources I see that there are different numbers for precipitation versus electrical resistance grading. The former stops at JIS 3000. At low grits they are identical but by 3000 they diverge significantly, particularly in the maximum particle size spec (which is not represented in my chart). I chose to include only the electrical resistance grading but I could include the precipitation values in a separate column if there is demand.


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## Mr.Wizard

apicius9 said:


> Very nice work, thanks! Just to better understand - what is the norm for ordinary American sandpaper?



I have updated the chart to include ANSI Coated values from B74.18-1996 as sourced from http://www.uama.org/Abrasives101/101Standards.html. This data was apparently available all along but I thought the described click-for-detail function was broken because my browser was set to block pop-up windows.


Be aware however that high ANSI Coated grit numbers are apparently a deprecated standard as the 2006 revision of B74.18 does not include any values above 600, and what it does include match ANSI Bonded values.

As always please see the README for additional and up-to-date details.


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## Spurr

Can you include Edge Pro stones within your table ?


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## Nemo

Spurr said:


> Can you include Edge Pro stones within your table ?


EP stones use the FEPA-F grit scale.


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## Mr.Wizard

Spurr said:


> Can you include Edge Pro stones within your table ?



The original Edge Pro stones are marked in red, as indicated by "BORIDE EdgePro stock" and the arrow from the adjacent column. If you are referring to the new Diamond Matrix resin-bond stones, they will be added shortly.


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## Mr.Wizard

The chart has been updated but it appears there is some caching here so it is not showing; click on the image to view the current version. Please also see the README for significant changes.


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## Mr.Wizard

The chart has been updated to revision 9. Again caching on this forum seems to prevent showing the change immediately. I am also having service issues with my ISP so if you get a "403 Forbidden" error refresh the page until the error goes away.


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## Caleb Cox

Can anyone volunteer a Horiba laser scattering particle size distribution analyzer? Where are Knife Stone Nerds?!


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## Mr.Wizard

The chart has been updated to revision 12. This forum uses caching so it may take a while to appear in the first post, it is live on the site linked.


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## Mr.Wizard

The chart has been updated to revision 13. Macrogrits have been extensively revised; see the README.txt for details.


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## whirlwynds

Thank you for your hard work on this chart. I consult it at least once a day!


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## cotedupy

This is excellent, thank you!

One suggestion simply in terms of presentation - I'd be tempted to try running some very light coloured, dashed, horizontal lines across it, for easier ref to the micron scale at the sides, and comparison of different abrasives.

You might find you feel the effect clutters what is already a lot of information. But often this kind of thing does the opposite; and is barely noticeable until you want it, while seeming to make things neater / more organised.

[A famous and quite interesting example of this kind of static reference is on the London Underground Map. It's not quite the same as a chart obviously - but in terms of trying to present easily a huge amount of slightly abstract information in a comprehensible way - similar ideas can apply. You could take the London Underground every day for decades and perhaps not notice the Thames on the map. But it's there, very light, in the background, and if you take it away it makes 'The Diagram' (as people who are interested in Harry Beck's design call it), far more difficult to use.]


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## Mr.Wizard

cotedupy said:


> One suggestion simply in terms of presentation - I'd be tempted to try running some very light coloured, dashed, horizontal lines across it, for easier ref to the micron scale at the sides, and comparison of different abrasives.



Thank you for your critique. I need this kind of feedback. Through revision 9 I used horizontal grid lines. In revision 10 I changed to the widely spaced gradient bars, noted at the time as experimental, and continue to use them as the default in revision 13. This seemed to de-emphasize precise translations across columns which—as explained in the README—are often meaningless, and visually the chart seemed a little cleaner without them. Nevertheless I am not married to this style and I still use the grid lines if requested on licensed versions. With your feedback I might return to them in the public revision 14.


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## cotedupy

Mr.Wizard said:


> Thank you for your critique. I need this kind of feedback. Through revision 9 I used horizontal grid lines. In revision 10 I changed to the widely spaced gradient bars, noted at the time as experimental, and continue to use them as the default in revision 13. This seemed to de-emphasize precise translations across columns which—as explained in the README—are often meaningless, and visually the chart seemed a little cleaner without them. Nevertheless I am not married to this style and I still use the grid lines if requested on licensed versions. With your feedback I might return to them in the public revision 14.



A good point about the gradients rather than precise translations. Another option to maybe play around with if you fancy might be to run the Micron scale, highlighted, in a column down the centre of the chart rather than / in addition to the scale at the sides. Which might help anchor a lot of information that sits slightly abstracted in the middle(?)

Again you may have tried that already and thought it didn't work as well. But might be worth looking at if not...

(I can't btw see the readme... I get a Server IP address error message.)


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## Mr.Wizard

cotedupy said:


> Again you may have tried that already and thought it didn't work as well. But might be worth looking at if not...
> 
> (I can't btw see the readme... I get a Server IP address error message.)



I haven't, but as the chart gets wider and wider I can see the value in the suggestion.

Would you try loading the readme again? The server has given intermittent errors before but usually hard refresh (Shift+F5) fixed it.


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## cotedupy

Mr.Wizard said:


> I haven't, but as the chart gets wider and wider I can see the value in the suggestion.
> 
> Would you try loading the readme again? The server has given intermittent errors before but usually hard refresh (Shift+F5) fixed it.



Still doesn't work for me I'm afraid. Attached is a screenshot of the error message I get.


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## Mr.Wizard

Revision 14 is live.


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## jwthaparc

I've never even heard of some of these abrasives. GREAT JOB! 

Idk how many times I've used your older versions of these charts to compare abrasives. You really are doing the metal grinding world a service.


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## Mr.Wizard

jwthaparc said:


> I've never even heard of some of these abrasives. GREAT JOB!
> 
> Idk how many times I've used your older versions of these charts to compare abrasives. You really are doing the metal grinding world a service.



I am glad you find this project of value. If you'll pardon the plug: if you would like to support my work I sell prints in poster sizes or on water resistant paper. I also accept donations.


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## jwthaparc

Mr.Wizard said:


> I am glad you find this project of value. If you'll pardon the plug: if you would like to support my work I sell prints in poster sizes or on water resistant paper. I also accept donations.


I would actually love a print. I can't buy one right this second (see my wip thread for details there ). But I would love to when I get some extra change. Where can I find them for sale?


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## Mr.Wizard

jwthaparc said:


> I would actually love a print. I can't buy one right this second (see my wip thread for details there ). But I would love to when I get some extra change. Where can I find them for sale?



My email is on every revision of the GLGC. I look forward to hearing from you.


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