Abrasives in Micron Scale

[Mr.Wizard]

You’re welcome! It took a lot of work to get to this point.

The ANSI column in the chart is for loose or bonded abrasives like stones rather than coated abrasives like sandpaper. According to http://www.uama.org/Abrasives101/101Standards.html there is also apparently an ANSI coated standard (“ANSI B74.18-1996, currently under revision”) but I was unable to include it in the chart. (This is noted in the README; please do take the time to read that file.)

I would not be so quick to assume “ANSI coated” for sandpaper as I have not seen product clearly specified in that standard. I have seen products clearly specified in JIS, FEPA-P, and CAMI; I believe Norton makes all three if I recall correctly. According to the charts on the page linked above the elusive ANSI coated values seem to line up quite well with JIS 1998, though tightness of grading is not identical, so if you do actually have ANSI coated paper you could look at those values for a rough guide.

The P2500 paper is clearly marked so among the three samples I think it is the best to use as a reference. I shall guess that your 600/800 3M paper is CAMI graded. This would put it as noticeably coarser than P2500. If the difference still seems larger than expected look closely at both products: a (semi) open coat will feel coarser than a closed coat and also leave a rougher finish. If that still cannot explain your observations please take a picture of the backs of your 600/800 sheets and I will see what I can find.

The Nikken 3000 paper is quite likely J3000 as it is made in Japan. This would make it a good choice to follow P2500, all else being equal. (But please note the discussion above; an average particle size alone is in no way sufficient to determine abrasive performance.)

The 3M 2000 is the hardest to figure out. I have repeatedly looked for clear documentation from 3M and not found it for this product. I did find micron equivalents for their Wetordry™ Polishing Paper and included them in the chart. Perhaps working together we can figure out what is most likely. Does your 3M 2000 paper appear to be coarser than both the Nikken P2500 and “3000” paper that you have?

The “Diamond compound” column in my chart is not based on the Wicked Edge pastes. Rather it is based on the coloration of diamond compound from a number of supplies which seem to be in at least partial agreement. (This also is stated and further detailed in the README.) The Wicked Edge pastes are clearly marked, as are the strops I believe, so it seems less useful to catalog those. My hope is that the compound colors on my chart give a “best guess” for a diamond compound that is unmarked or has had the label obliterated.

As you probably are aware the speed and finish from a compound greatly depends upon the applicator used, with harder substrates causing the particles to cut deeper into the workpiece. You can see from http://www.wickededgeusa.com/grits-comparison-chart-for-the-wicked-edge-sharpener/ that the 14 micron diamond compound on leather gives a completely different finish from 14 micron stones; it has polish far beyond its apparent grit size.

[tcmeyer]

I did some searching and find that there are a bunch of different grit definitions. There’s the Federation of European Producers of Abrasives (FEPA) which has definitions for both paper and solid abrasives. When you see paper with a “P” designation (ex.: P1800) that’s the FEPA paper standard. There’s also the ANSI standard. Some use the maximum size of any particles in a batch to define the batch size, or they may use the average particle size. None seem to have their charts go beyond 1000 grit, which seems to be the finest you can run through a sieve. For smaller particle sizes, I think they just grind away at a batch until it visually seems on average to meet the standard they are looking for.

I misspoke (?) earlier when I said that the grit number is the inverse of the particle size in inches. It’s more correct to call it the reciprocal of the particle size in inches.

For example: A 3 micron particle size would work out to 0.0001181 in inches. The reciprocal is 8,467, or about 8500 grit.

According to the chart by Advanced Abrasives, you could find 3 micron particles in anything between 6,500 and 11,000 mesh. Grits of 6,500 could have particles ranging between 3 and 5 microns, while grits of 11,000 could have particles ranging from 1 to 3 microns.

I’d infer that this could be one of the reasons why we see large differences in the scratch patterns of various forms of abrasive media. To-may-to, to-mah-to. So, just how red are your tomatoes?

Maybe there’s some guy in the quality lab, looking down a microscope, saying “Yup. There’s some big ones and some little ones, but overall, this batch looks like 3 micron to me. Let’s call it 8,000 grit and sell it to Norton”

As an old friend would say, “Machts nichts.” For our purposes, it doesn’t matter, but now I think I know what the numbers are supposed to mean.

1 user thanked author for this post.

GJHM28

[Mr.Wizard]

tcmeyer, is your reply primarily to Cliff Curry or to me? I shall respond as though you were addressing me.

Yes, “P” grades are FEPA-P, as shown in the chart. The acronym FEPA is also defined in the README. I did not feel it was necessary to say “when you see ‘Pxxx’ it means FEPA-P” as that seems tacit. Do you disagree?

Regarding ANSI please see my post above and also the README. There is apparently an ANSI coated standard that goes to 8000 and is nearly identical to JIS, but I have been unable to find a free reference and since the standard is “under revision” I don’t feel like paying for an obsolete technical document. From the UAMA link above:

Caveat: the UAMA graphics below use JIS 1987 rather than the newer 1998 revision, and FEPA 1993 revision rather than the newer 2006.

“ANSI B74.18-1996 (shown as ‘Coated’ in the exhibits)”

Note that at higher values JIS and “Coated” are co-labeled and apparently equivalent. However D50 values are not the only specification in a grit standard; it is not sufficient for a grit to be nominally 3 micron as you describe. Also from the UAMA page we have the D3 and D94 limits for certain grits:

Note that (ANSI) “Coated” appears to be more tightly graded than JIS at lower grits and far more tightly graded than ANSI B74.10. (Incidentally JIS is considerably tighter than FEPA-P, not shown.) At higher grits JIS and ANSI coated are again co-labeled.

Attachments:

• Exhibit4.jpg
• Exhibit7.jpg

[CliffCurry]

Thank you for the reply, I will have to slow way down and take the time to read more thoroughly(especially the readme!) It is really a lot of information to take in at once, and I got a bit excited to see in black and white what has been a huge mystery to me since I started.

You have already clears up many of the questions I have had for a long time. These are the grits currently available/used by me in progression after the 1000 grit diamond paddles:
p1000 ≈ 20µ
p1200 ≈ 16µ
p1500 ≈ 13µ
3M 1500 – ? (feels a bit smoother then p1500)
3M 2000 – ?
p2500 ≈ 9µ
3000 ≈ 4µ (if it’s the “J” type which it does seem to be)

The Nikken 3000 paper is quite likely J3000 as it is made in Japan. This would make it a good choice to follow P2500, all else being equal. (But please note the discussion above; an average particle size alone is in no way sufficient to determine abrasive performance.)

The J3000 does perform well following the P2500. A large part of my excitement was in the new Micro ceramics, and micron sprays that are in route. Im looking forward to extending my limits downward further and the chart is already proving invaluable as a guide.

The 3M 2000 is the hardest to figure out. I have repeatedly looked for clear documentation from 3M and not found it for this product. I did find micron equivalents for their Wetordry™ Polishing Paper and included them in the chart. Perhaps working together we can figure out what is most likely. Does your 3M 2000 paper appear to be coarser than both the Nikken P2500 and “3000” paper that you have?

The 3M products do seem to be the missing piece for this area. Strange since it seems to be widely available. The 3M 2000 does feel slightly more course the P2500. The P1500 definitely feels more course the the 3M1500 but question if it could be open/closed coat differences etc. I agree the 3M information is elusive, I did find a woodworking website that said, “1000 to 2500 grits are made from 3M’s 401Q Silicon Carbide abrasive paper – graded in the ANSI/CAMI grit scale.” Not very helpful since isnt that 2 scales?

Time to go read that readme doc :whistle:

1 user thanked author for this post.

GJHM28

[Mr.Wizard]

Please let me know what needs further clarification. It will help me improve the README.

I think I found the woodworking page you referenced. I have seen similar statements before, sometimes contradictory. I have yet to see a proper specification in an official 3M publication. Based on your descriptions and a bit more digging I think that 3M is using ANSI B74.18-84 (ANSI coated), not yet on my chart. I cannot find this in any English publication from 3M but I did find a few references in Spanish documents, e.g.: 3M 411-Q.pdf. There is no guarantee that this is used in their other products but it does align with what you are observing. If I am correct the 3M 1500 should very similar to P2500 but (perhaps) graded more tightly.

Incidentally the “84” in ANSI B74.18-84 means 1984 which leaves me wondering why 3M would be using such an old standard. There are 1996 and 2006 revisions of this standard, and even the 2006 one may be under revision if I interpret this correctly: Status_of_Standards_2013-09-05_ANSIpublic.pdf.

[tcmeyer]

Thanks Mr Wiz, but I was replying to my own earlier misstatement.

I think this discussion has gotten too technical for the vast majority of readers here. It has for me. So far, the best (most relevant) info I’ve seen has been Clay’s array of photos, relating scratch patterns to particular stones for empirical data . Maybe it’s just time for an updated version including the current crop of stones and abrasives.

[Mr.Wizard]

My questions are in the area of the high grit sandpapers. I am using a combination of papers from 3M that I guess are ANSI, and I found some 2500/3000 grit paper from an auto detail supply company locally. My results are good and consistent and the progression is smooth but on the charts it seems there is now way it could line up.

For example my P2500 paper is much much finer then a 600-800 ANSI paper from 3M. The 3000 grit is so smooth it feels like vellum or something…any help greatly appreciated.

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 the ones it does include match ANSI Bonded values.

[CliffCurry]

Thank you Mr Wizard!

In the last little bit I’ve adopted a less thinking/more doing approach until I can get a scope to see what’s really going on down there.

I’ll check the updated chart n compare to my own results just for clarity where the real world meets the chart taking a grain of salt alongwith the numbers.

I have the chart taped right above my bench and refer it daily for my progression across the different media. It really is invaluable. Much Aloha!

[Mr.Wizard]

As this chart nears maturity I again ask for feedback on its design and content. All feedback is appreciated but here are some seed questions:

Are there aspects that take too long to understand or remain entirely opaque to you?

Is there a standard or product line that you wish were included that is not?

Would additional common size references such as Table Salt be helpful, or useless clutter?

Are the designations of the red-colored items in certain columns apparent or confusing?

Are the black and orange vertical lines understood and appreciated? Are there too many or too few of them?

Does any data stand out as likely being in error?

[Ziggy]

Gotta find me those A300 Trizacts in 1 x 42.
I’m guessing their scratch pattern will be minimal compared to other belts.

[Mr.Wizard]

Gotta find me those A300 Trizacts in 1 x 42.
I’m guessing their scratch pattern will be minimal compared to other belts.

Those are available here: 1×42-80 A300CF “Gator” 337DC Trizact Aluminum Oxide. 3M states that it will finish like an 80 grit belt which is why it is marked as such. Realistically I wouldn’t expect them to cut like a 50 grit belt as (I believe) Trizact belts are intended for finishing, not roughing.

[Ziggy]

Gotta find me those A300 Trizacts in 1 x 42.
I’m guessing their scratch pattern will be minimal compared to other belts.

Those are available here: 1×42-80 A300CF “Gator” 337DC Trizact Aluminum Oxide. 3M states that it will finish like an 80 grit belt which is why it is marked as such. Realistically I wouldn’t expect them to cut like a 50 grit belt as (I believe) Trizact belts are intended for finishing, not roughing.[/quote]

Thanks Mr Wizard.
I actually think I have them, not the same as the A100 style where the abrasives are closer together.
They are more the gator style.
They leave scratch patterns similar to other belts.

Hope was that they would have the same tight pattern as the 100 and others.
I’ll pull them out but believe they leave a pretty rough scratch pattern with those large spaced diamonds as they are Gators.

I saw a 160, it may be in the same trizact pattern if I can find it.

Looking for rough work without deep scratches.

The A100s are great, but wear fast.

[Mr.Wizard]

Let me see if I understand: you want the coarsest non-“Gator” Trizact belt available? Do you know the product number of the (finer) belt that you do like?

[Ziggy]

Let me see if I understand: you want the coarsest non-“Gator” Trizact belt available? Do you know the product number of the (finer) belt that you do like?

Yep.
They produce a finer pattern. I don’t know the number, just saw trizact A300 on the chart and said “do want!” 🙂

[Mr.Wizard]

Would you mind posting this question in a new thread? I’d rather keep this one more focused, yet I also want to see if I can help you track down a product to try.

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