# testing abrasion rate (testing stone speed)



## inferno (Aug 23, 2020)

i wanted to see how much steel my some of my stones remove, so i tested that.
test subject was a stainless clad aus-8 deba that i had done some destructive tests with.
i did 300 "cycles" on each stone and then simply weighed the blade inbetween.

1 cycle = 1 forward and 1 backward stroke.
the applied force was whatever i deemed suitable for that particular stone. basically what i would normally use when thinning/polishing with that stone.

the scale has a resolution of 10mg, repeatability of +-10mg, linearity of 30mg (not relevant in this test), warmup time 2min. calibrated just before.
i averaged several measurements for each stone.

all stones were flattened on the diaflat 160 before use, except the 12k shapton, it was flattened on the 12k superstone.







results for 300 cycles:

390mg - shapton pro 220 
290mg - worn diaflat 160 
290mg - worn atoma 400 
410mg - glass 220 
270mg - glass 500 
240mg - shapton pro 1k 
190mg - glass 1k 
240mg - naniwa pro 800 
130mg - naniwa pro 2k 
110mg - glass 2k 
120mg - shapton pro 2k 
70mg - glass 3k 
40mg - glass 4k 
10mg at most - shapton pro 12k


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## inferno (Aug 23, 2020)

next week i will recieve some more stones to try. shapton pro 120, both out of the box speed and then flattened on diamond and with SiC powder. is it faster than the 220ies?? who knows.

i will also try flattening/conditioning with SiC powder on the 220ies and the glass500. I have a feeling those 3 stones really need SiC powder to make them cut well. but we'll see how much faster they get, if any at all. my glass 500 feels like a 1k after the diamond plate. Might even try SiC on the 1k stones too. 

then i have a green 240 sigma incoming, and also a few other ones that i have been wanting to try for a long time.


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## IsoJ (Aug 23, 2020)

This is interesting, looking forward of seeing how the SiC powder affects on the results.


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## M1k3 (Aug 23, 2020)

When you condition the SP 120, I'd test conditioned as coarse as possible and as close in grit without going finer.


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## nexus1935 (Aug 23, 2020)

Very interesting test, thanks for sharing!


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## ModRQC (Aug 23, 2020)

I’m kindly comforted with your results concerning the NP800. A lot of steel removed considering the grit. I feel like it’s a marvelous « coarse-mid » stone, apt for thinning, great and speedy and clean beveling, then quick to a burr and a quite effective one stop stone for suitable steels, and just as effective a start to a progression with finer steels.


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## inferno (Aug 24, 2020)

M1k3 said:


> When you condition the SP 120, I'd test conditioned as coarse as possible and as close in grit without going finer.



i got the stone today and i will test it ootb, diamonds, 60 and 120 grit SiC.
also got the green sigma 240 and the blue imanishi 400. 
the 120 feels ultra coarse, i mean ultra coarse ootb  i wonder if i can get that surface back. i think i will.

dont know if i will have to do anything to keep the imanishi cutting good. its supposed to be a softer stone than the shaptons. I'm guessing it will release some abrasive.

the 240 sigma is sintered "green SiC" so it should in theory be self refreshing as opposed to black SiC.


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## Wander Vanhoucke (Aug 24, 2020)

This is very interesting... One step closer to taking subjectivity out of the equation with stones


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## M1k3 (Aug 24, 2020)

inferno said:


> i got the stone today and i will test it ootb, diamonds, 60 and 120 grit SiC.
> also got the green sigma 240 and the blue imanishi 400.
> the 120 feels ultra coarse, i mean ultra coarse ootb  i wonder if i can get that surface back. i think i will.
> 
> ...


You can definitely get the surface back on the SP120. I'm just curious if refreshing it super coarse or near it's grit actually makes a difference, not just my perceived difference. The sigma releases more grit than SP120 so it does self refresh.


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## ma_sha1 (Aug 24, 2020)

Awesome test


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## inferno (Aug 24, 2020)

ok the results are in:

590mg - 120pro out of the box
380mg - 120pro after diamonds
480mg - 120pro after 120grit SiC
500mg - 120pro after 60grit SiC

380mg - glass220 after 60 grit SiC
410mg - glass220 after diamonds (from post above)

340mg - pro220 after 60grit SiC
390mg - pro220 after diamonds (from post above)

320mg - glass500 after 60grit SiC
270mg - glass500 after diamonds (from post above)

diamonds= diaflat 160, half worn.


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## ModRQC (Aug 24, 2020)

OOTB coarseness is difficult to achieve then...


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## inferno (Aug 25, 2020)

ModRQC said:


> OOTB coarseness is difficult to achieve then...



yes. at least on the 120 pro. but you can get almost there.

on the 220ies i can get a very coarse surface, but its like it gets worn away within 50 strokes. then the stones kinda revert to what they want to be anyway.

maybe i'm weakening the stone around the abrasives too much so they fall off quicker with the 60 grit powder?
maybe the abrasives stick around a bit longer without getting torn out after diamonds since its more to support them. and maybe the more continous surface is faster since i get more abrasives in contact with the steel?

I might also actually be dulling the abrasive with the SiC whereas the dmt can actually cut the abrasive. i dont know.

lots of weirdness going on.

SiC is a lot quicker as a method than the dmt for flattening though. about 10x as fast i'd say.

all stones feel different (and imo better) after the SiC surfacing though vs diamonds.


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## inferno (Aug 25, 2020)

Also this is on mostly i guess austenitic stainless since most of the deba (90%) is some soft ss like 304. 

All these results might be different on lets say hardened monosteel. i will have to try that too. just wanted to get hold of something thick and hardened, preferably some wide bevel cheap german, but still quite hard.


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## ModRQC (Aug 25, 2020)

inferno said:


> Also this is on mostly i guess austenitic stainless since most of the deba (90%) is some soft ss like 304.
> 
> All these results might be different on lets say hardened monosteel. i will have to try that too. just wanted to get hold of something thick and hardened, preferably some wide bevel cheap german, but still quite hard.



The results could very well be different but I’m guessing they still would be consistent with what you got with your aus-8, at least not majorly different that a high removal rate would become a low removal rate on another steel?


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## Alder26 (Aug 25, 2020)

Very interested to see what the sigma 240 looks like.


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## inferno (Aug 25, 2020)

ModRQC said:


> The results could very well be different but I’m guessing they still would be consistent with what you got with your aus-8, at least not majorly different that a high removal rate would become a low removal rate on another steel?



probably the results would be quite similar. but you never know (as we can all see). i'm thinking about just using some high surface area hardened steel from the scrap container from my job, chop it up to a workable piece and grind away. i have some big bearing races in 52100. probably 62-63 hrc or so.


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## inferno (Aug 25, 2020)

Alder26 said:


> Very interested to see what the sigma 240 looks like.



me too but its not gonna happen today, maybe in a few days. 

i have a few other stones to test. all the juumas for example. i think i have maybe 15 more stones to test. the 240 will be one of the first for sure.


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## Simme (Aug 25, 2020)

Looking forward to it.


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## inferno (Aug 25, 2020)

i think the sigma 240 will beat the other stones. but it will probably also wear a lot more.

--------------

it might seem like you just grind away and put the blade on the scale, 2 minutes and done!

but its a bit more things involved. the blade has to to be in the exact same position, and has to be completely dry. the scale has to warm up (some milligram scales takes 2 hours to warm up), you have to calibrate it. i cant even breathe on it or it will show inaccurate values. then you have to do several weighings. and kinda see where the center of all of those are (taking the repeatability in consideration). and thats the real number.


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## Alder26 (Aug 25, 2020)

Such an interesting experiment! Especially to see that some stone cut nearly as fast as stones that are half the grit rating. Particularly useful to someone trying to flatten a bevel as fast as possible. In many cases you might not save that much time by using a 200ish grit stone if you have have a fast 400-500


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## ModRQC (Aug 25, 2020)

inferno said:


> probably the results would be quite similar. but you never know (as we can all see). i'm thinking about just using some high surface area hardened steel from the scrap container from my job, chop it up to a workable piece and grind away. i have some big bearing races in 52100. probably 62-63 hrc or so.



I may not have been perfectly clear. Obviously if the steel is much harder your results will vary greatly but from stone to stone, the ones that removed the most metal out of your AUS will also be among the ones to remove most metal from a harder steel, unless somehow the abrasive is really particular to steel.


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## spaceconvoy (Aug 25, 2020)

inferno said:


> i think the sigma 240 will beat the other stones. but it will probably also wear a lot more.


would be very cool if you could also weigh the stones before and after


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## inferno (Aug 26, 2020)

some of the stones are soakers so they take about 1 week to dry. its not very practical


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## KingShapton (Aug 26, 2020)

inferno said:


> i have a few other stones to test. all the juumas for example.


I'm really looking forward to the results and impressions of the Juuma stones.

I have also been tempted to buy these stones many times, but no information is available about them and at the moment I avoid blind purchases. I already have more than enough stones ...


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## inferno (Aug 26, 2020)

i actually teested the juuma stones 5 minutes ago. but only on a test knife. no weighing. i will write a small review in the juuma thread.


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## KingShapton (Aug 26, 2020)

inferno said:


> i actually teested the juuma stones 5 minutes ago. but only on a test knife. no weighing. i will write a small review in the juuma thread.


Thanks in advance


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## inferno (Aug 26, 2020)

340mg - sigma 240
230mg - bester 400


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## RDalman (Aug 27, 2020)

Great thread. It also tells a hint of how slow thinning on benchstones really is. 300 pulls for 0,5g  
Maybe I should measure grams lost in one pass on the grinder on a fresh 60 grit sometime.


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## KingShapton (Aug 27, 2020)

RDalman said:


> Maybe I should measure grams lost in one pass on the grinder on a fresh 60 grit sometime.


Please don't do that, otherwise I can see that in the future belt grinders and belts will be tested instead of rough stones ...

And I can't possibly explain to my wife why I now need a belt sander for home ...,


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## kayman67 (Aug 27, 2020)

spaceconvoy said:


> would be very cool if you could also weigh the stones before and after




This gives you a general idea about what to expect. Sure, there are more factors to consider, but the work would have been crazy. A few years back I did something by also measuring the stones and other stuff and eventually gave up.


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## inferno (Aug 27, 2020)

RDalman said:


> Great thread. It also tells a hint of how slow thinning on benchstones really is. 300 pulls for 0,5g
> Maybe I should measure grams lost in one pass on the grinder on a fresh 60 grit sometime.



for me, if i didn't have to count the strokes i would do about 300 strokes in about 3 minutes, so its not really that big of a hassle.


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## inferno (Aug 27, 2020)

i'm encountering a weird problem with the 800 juuma. the cladding of the test knife seems to get simply torn off in big chunks, and then the chunks kinda plow very deep scratches in the stone. i saw the same thing on the diaflat and the atoma 400, it basically made scratches in the nickel plating with torn off diamonds/cladding. i think the cladding is simply too soft for some stones. i'll see if i can get it to work.


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## inferno (Aug 27, 2020)

for this test i switched test blade to a single bevel santoku made out of 80crv2, at 62-63hrc.
basically the juumas would have been impossible to test with the old test blade. they just tear out the cladding.

obviously the numbers in this post will only be relevant for this blade. 
i had to come up with something to test the juuma stones. and this was the easiest.

so i'm basically testing them vs the shapton pro 1k and 2k since many people know them.

110mg - pro 1k on dmt

20mg - juma 800 on dmt 
170mg - juuma 800 on SiC120 grit

80mg - juuma 1200 on dmt
150mg - juuma 1200 on SiC120 grit

80mg - pro2k on dmt

50mg - juuma 2k on dmt

the juumas really need the correct surface to work imo. and the dmt was not it.


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## big D (Aug 29, 2020)

Always appreciate information about things. Thanks for sharing your findings.
D.


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## Carl Kotte (Aug 29, 2020)

RDalman said:


> Great thread. It also tells a hint of how slow thinning on benchstones really is. 300 pulls for 0,5g
> Maybe I should measure grams lost in one pass on the grinder on a fresh 60 grit sometime.


Hmmm, I wonder why it took me so long to thin the giant Sab.


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## RDalman (Aug 29, 2020)

Carl Kotte said:


> Hmmm, I wonder why it took me so long to thin the giant Sab.


With that terrible semi it was sporting I'm not surprised


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## Luftmensch (Jan 6, 2021)

Wow!



Super awesome comparison. Thanks for taking the time to do this! Really fun to view the results.


I found the 120 pro to feel unpleasant before a slurry forms (to my tastes). It is surprisingly hard for a low-grit stone. Until a slurry forms, it feels like the steel is skating across the surface. I started adding a small amount of 280x* SiC powder to the stone before honing. This almost instantly creates a nice crunchy slurry. I think it cuts faster... even if it isn't... it feels nicer 



* Whatever equivalent grit that ends up being...


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## inferno (Jan 6, 2021)

putting some powder between 2 coarse stones seems to be a very quick way of getting a good surface on them too.


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## jwthaparc (Jan 6, 2021)

Oh btw, this is off topic. When I compared the speed of the venev stone it was pretty much identical to all the others. I didn't do it in a scientific way like yours. I just dulled an aus6 (I believe) kai professional santoku, and brought the edge back again with the stones. I haven't tested the 700ish grit side against the other stones I have in that range, but from using it so far it seems like it will perform much like the other stones I have in that range.

I really think where it will shine is when I finally get to use it on supersteels.


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## Deadboxhero (Jan 6, 2021)

How much pressure was applied when using the stones? How much variation in pressure used?


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## inferno (Jan 6, 2021)

Deadboxhero said:


> How much pressure was applied when using the stones? How much variation in pressure used?



i have no idea. just the max i could typically do myself if i wanted to thin something.


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## Kitchen-Samurai (Jan 6, 2021)

Thanks Inferno, this is really great! As Deadboxhero said, pressure will be an important variable, especially if you do the testing all in sequence (and might get tired at the end...). But still, really cool and helpful data. And it underlines what many of us have discovered: conditioning of stones, and especially of hard coarse stones is critical.


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## inferno (Jan 6, 2021)

this was not a lab test. its a test of how much steel i could remove in 300 strokes when pushing the individual stones to the realistic max (for me).

using a fixed pressure is a dual edged sword imo. lets say you do do a fixed pressure. and you get this or that result for stone x or y.

this does not really tell you much about how it will work at home when using it, since for coarse stones you usually want them to be as fast as possible. faster than fine stones. so when you use these, you push harder. i dont use my coarse stones with light pressure since it makes absolutely no sense. 

basically you need a certain pressure to even initiate a cut. and the bigger the abrasive particles the higher the pressure obviously since your removing a bigger chunk of steel for each particle. 

i dont use my fine stones at the pressure i did in this test usually. since they are fine stones and the goal for them is not to remove as much metal as possible. but if you only had 1 stone and you needed to remove a lot of metal you would use the max pressure you could for these.

as i said, this is not a lab test. this is test where i tested how much steel i could remove when i pushed these stones to the max. and its full of different non controlled parameters. such as: did i use the same pressure on all stones? highly unlikely. i just tried to push them to the max. remove as much metal as possible in 300 strokes without going to unrealistic high pressures. but something i would do myself when using these stones.

did i do the exact same length all the time?? highly unlikely, and also the stones are not even the same size to begin with.

i however did 2 stones 2 times, just to see how accurate this would be. i think it was the shapton pro 220 and maybe the 1k or the 800 naniwa. and the results was +-10mg so i was happy with that. also the scale is only so accurate (you can find the data in the first post), and you kinda need to put the blade in the exact same position every time you weigh it.

it is what it is. 

i still think its kinda accurate. this is what most people can expect to get out of these stones when they push them to the max themselves. not talking the exact mg values but the internal ranking between the stones and the different grits. 

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i would also like to add something that might not be apparent. some of these values seems to be very close. the 220 pro is only like 50% faster than the 1k pro. and while this might be true. when you try thinning some crapola blade than needs a lot of work, even a 10% increase is worth it! 
you will basically find out that: this sh!t is taking forever, i need a coarser stone! there is a threshold of what is acceptable when doing a big "project" imo.

I remember having the 500 glass as my coarsest stone, and while its a fast stone. its not fast enough sometimes. and the 220ies are a big step up in reality. actually the 500 is never fast enough once you tried one of the 220ies.


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## jwthaparc (Jan 6, 2021)

inferno said:


> i would also like to add something that might not be apparent. some of these values seems to be very close. the 220 pro is only like 50% faster than the 1k pro. and while this might be true. when you try thinning some crapola blade than needs a lot of work, even a 10% increase is worth it!
> you will basically find out that: this sh!t is taking forever, i need a coarser stone! there is a threshold of what is acceptable when doing a big "project" imo.
> 
> I remember having the 500 glass as my coarsest stone, and while its a fast stone. its not fast enough sometimes. and the 220ies are a big step up in reality. actually the 500 is never fast enough once you tried one of the 220ies.



My baseline for what a slow coarse stone is was kind of thrown off. I went straight to the shapton 120 as my first coarse stone. So, I figured that is how fast coarse work should always be done.

Also a tip since I see you just bought the 120, do not wash off the slurry on this stone. It keeps the stone from clogging, and helps speed the stay high.


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