New diamond hones: Coarse grit feels finer than fine grit

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Papilio

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Sep 6, 2019
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Due to prolonged problems with wrist and shoulder I have not been able to do much sharpening during last months. Today I took two diamond sharpeners out of the drawer.
Both are new. One is Chinese - Made in China, coarse grit (360 JIS). I contacted the manufacturer, they confirmed grit and standard.
The second one is US - Made in China, fine (600) grit. I don‘t know what grit standard Lansky uses for their diamond plates / hones. Be it ANSI or JIS, it should be finer than coarse 360 grit.

To my surprise they feel the other way round. The coarse one feels much finer than the one that should be a fine diamond plate. As mentioned before both need to be broken in. As both are Made in China (and the Chinese Made in China is manufactured by a big name on the market that does OBM and ODM business) I can‘t imagine that quality will be much different. Especially as both sharpeners look identical in design, shape (only the bodys color is different).

I don‘t have a microscope to make a particle size comparison. I appreciate any advice.
 
I also use cheap chinese diamond plates so I would like to see a close-up photo of both plates before I give you a comment.
 
Might also be some perceived difference if the diamond is either monocrystalline or polycrystalline. Polycrystalline diamond, as the name implies, is basically smaller crystals clumped together, which would make them feel coarser initially. It's designed to break down with use into the fine-rated smaller crystals, so the diamond can keep on cutting rapidly without wearing too much. As it breaks down, the feel of it will get perceptably finer, as will the finished scratch patterns on the steel. I see these differences in two of the U.S.A. brands, DMT vs. EZE-Lap. DMT uses monocyrstalline diamond, whereas EZE-Lap uses polycrystalline (EDITED: ....or a blend of both - see my later reply in this thread). When new, the EZE-Lap feels much coarser than its grit rating would imply. But it gets finer with some use and the grit rating then starts to make sense in terms of the finish it leaves on the steel.

Might just use them for awhile and keep an eye on the finished scratch patterns to see if the coarser looks coarser and the finer looks finer. New diamond hones are always kind of hard to figure out initially, based only on how they feel.
 
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Link to photo / webhoster removed. See my third posting (posting #8 in total) for a new photo.

I don't know how to call them. Lansky calls it a retractable diamond pen. The Chinese one is called a "Multi-functional Knife Sharpener".
Both have different radii, like the Lansky Spyder Sharpener.

The photo seems to be the best as I can. That's my phone's camera max. zoom.
 
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Obsessed with Edges said:
Might also be some perceived difference if the diamond is either monocrystalline or polycrystalline. Polycrystalline diamond, as the name implies, is basically smaller crystals clumped together, which would make them feel coarser initially. It's designed to break down with use into the fine-rated smaller crystals, so the diamond can keep on cutting rapidly without wearing too much. As it breaks down, the feel of it will get perceptably finer, as will the finished scratch patterns on the steel. I see these differences in two of the U.S.A. brands, DMT vs. EZE-Lap. DMT uses monocyrstalline diamond, whereas EZE-Lap uses polycrystalline. When new, the EZE-Lap feels much coarser than its grit rating would imply. But it gets finer with some use and the grit rating then starts to make sense in terms of the finish it leaves on the steel.

Might just use them for awhile and keep an eye on the finished scratch patterns to see if the coarser looks coarser and the finer looks finer. New diamond hones are always kind of hard to figure out initially, based only on how they feel.
Click to expand...
How confident are you that EZE-Lap uses polycrystalline diamonds for their plated products?
 
Diemaker said:
How confident are you that EZE-Lap uses polycrystalline diamonds for their plated products?
Click to expand...
They or some of their vendors actually stated so, at some point in their product descriptions. Here's an example from Lee Valley Tools, describing EZE-Lap's paddle hones. They mention a blend of both mono- and polycrystalline in the product:
( Quoted from site: https://www.leevalley.com/en-us/sho...-and-hones/70638-eze-lap-diamond-paddle-hones )
"...With a blend of monocrystalline and polycrystalline diamond particles, these hones offer an excellent combination of cutting speed and durability. The monocrystalline particles cut aggressively but round over time through wear, eventually diminishing cutting speed. By contrast, while less durable, polycrystalline diamonds fracture to expose new, sharp cutting edges so that they continue to cut with speed, although with a finer, less aggressive scratch pattern."
Click to expand...

Edited to add:
I'm also reading that polycrystalline diamond is apparently less expensive to produce. This might hint at what most of the cheaper diamond hones would likely be using. It does track with EZE-Lap's pricing, which is less expensive than DMT with their monocrystalline diamond.
 
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I was able to look the photo just for a second before Imgur asked me to consent and share personal info. Of course I declined but looks like the bottom one is coarser.
When I get new diamond plates I break them in and kill some spikes with a piece of HSS steel. Then I chamfer the edges with toolshop file to break-off diamond bildup.
Usually I have no issues. The low grid contamination is about the same as on DMT or Spyderco plates and the same goes for diamond bild-up on the edges.
Anyway, break them in and see what you get.
 
My browser has problems with Imgur, too. Sorry for that. I don't use a image hoster regularly.
I tried another hoster. Hope it works better.

[url=https://postimg.cc/cKpy65zM][/URL]

You are right, the bottom ones feels coarser. It seems to be quite obvious as you were able to see this just by taking a glimpse. But: That's the fine 600 grit diamond.
 
Papilio said:
My browser has problems with Imgur, too. Sorry for that. I don't use a image hoster regularly.
I tried another hoster. Hope it works better.

[url=https://postimg.cc/cKpy65zM][/URL]

You are right, the bottom ones feels coarser. It seems to be quite obvious as you were able to see this just by taking a glimpse. But: That's the fine 600 grit diamond.
Click to expand...
For what it's worth, I've often not liked the smaller rod-type diamond hones - especially inexpensive ones. I have an old EZE-Lap pen-type sharpener that is much, much too rough for my liking and the rod itself is very small & narrow. Very little use on it, as I've always felt its roughness and unevenness left my edges more damaged by it than enhanced. Seeing the obvious bumps on your pictured hone (lower one) reminds me of that. Hopefully, those can be worked off with some use over time, or lightly rubbed off with something like a ceramic hone (I've done that before).

BTW, I'm not knocking all of EZE-Lap's hones. I also have an old EZE-Lap model M rod sharpener, larger than the one I mention above. It's the one housed in a brass casing which unscrews and flips around as a handle. That sharpener has become one of the better ones I've used. It's close to 40 years old by now, I think I bought it back in the 1980s. I also have an EZE-Lap folding sharpener, like DMT's Dia-Fold hones, in 400/1200 grit. It's also pretty good.
 
As I mentioned before I like those ceramic bone / crock stick sharpeners from Lansky. I use the Spyder Sharpener quite often to sharpen Swiss Army Knives or knives with a shorter blade in general. The profile of this ceramic hone is versatile, works for spoon knives or bread knives (with serrations), too. As both diamond stick sharpeners were on sale - I think I paid ~ 20€ for both - I thought I give them a try. I agree, they are narrow and might not be easy to use. The ceramic Spyder rod works better, although it is as narrow as the diamond ones. But I can hold in between thumb and pointer. The plastic casing is a little bit annoying. I would prefer if it would be possible to take the diamond rod out of the casing.

The lower one (that is the "finer" that feels coarse) is from Lansky. The upper one is the much cheaper Chinese made. As the Lansky rod usually is ~30€ I have doubts if it would be worth the money.

I think I will take an old, cheap paring knife that has seen a lot of abuse by carbide pull-through sharpeners for breaking in the diamond rods. I am curious how that works.

Thanks for your answers.
 
Yes, much better... I can see your photo now without sharing my personal info.

If I compare your stones to my diamond plates yours look somehow coarse....more like #180 and #240 grit.
Here are my plates to compare. They are broken in and used for some time but.... Those are from one of my 'field' sharpener.
https://drive.google.com/file/d/1JCJdAGkNKcB6ItUR2potVrMWoYa84yrW/view?usp=drivesdk

Here are plates from my folding sharpener:
https://drive.google.com/file/d/1Qfofc7vrilFAPAmhmpWtNdnDXi7uoTpH/view?usp=drivesdk

https://drive.google.com/file/d/1JEeYPM9q94-VJtlxbaxqwwV4Ki_dvvjz/view?usp=drivesdk

I also have this $5 (#320/#600 grit) folding sharpener from A**ex***ss and it works just fine. The #320 grit is ok and #600 grit plate feels just a little coarser as my other #600 grit plates but no big deal. By the way, this is not my photo...I have my sharpener in my drawer at work.
https://drive.google.com/file/d/1JFyCF_Cjn2Yn2LoeDcvGFuqkAnIvBlE1/view?usp=drivesdk

Just for my curiosity, are those some sort of pocket sharpeners?
 
Obsessed with Edges said:
They or some of their vendors actually stated so, at some point in their product descriptions. Here's an example from Lee Valley Tools, describing EZE-Lap's paddle hones. They mention a blend of both mono- and polycrystalline in the product:
( Quoted from site: https://www.leevalley.com/en-us/sho...-and-hones/70638-eze-lap-diamond-paddle-hones )


Edited to add:
I'm also reading that polycrystalline diamond is apparently less expensive to produce. This might hint at what most of the cheaper diamond hones would likely be using. It does track with EZE-Lap's pricing, which is less expensive than DMT with their monocrystalline diamond.
Click to expand...
My sources charge close to 10 times more for poly vs monocrystalline diamonds. The line of thought I have always heard of is you want mono if it's fixed and poly if you want to polish, which is often with loose abrasives. If the abrasive is fixed you don't want it breaking down.
 
TheOne45 said:
Just for my curiosity, are those some sort of pocket sharpeners?
Click to expand...

Yes, they are. The rod is retractable (well, the tip of the rod sticks out of the casing).
[url=https://postimg.cc/Q92sT1Q2][/URL]

The third image shows the Chinese Sharpener next to Lanskys Spyder Sharpener. As you see they have more or less the same cross section. That's why I bought the diamond sharpeners. For field use as well as for sharpening other than plain edges.
Comparing mine with yours they look very coarse. Even Fallknivens fine 600 grit diamond plate - which comes quite coarse when new - does not feel as rough / aggressive / coarse as the one made by Lansky.
 
Papilio said:
The third image shows the Chinese Sharpener next to Lanskys Spyder Sharpener. As you see they have more or less the same cross section. That's why I bought the diamond sharpeners. For field use as well as for sharpening other than plain edges.
Comparing mine with yours they look very coarse. Even Fallknivens fine 600 grit diamond plate - which comes quite coarse when new - does not feel as rough / aggressive / coarse as the one made by Lansky.
Click to expand...
I see now. You need this particular shape of diamond stones.
Break then in. Well, you can't make #600 grit from #180 grit but you will make them somehow less aggressive.

I only have ordinary knives so I only use flat diamond plates.
By the way, I got inspiration from this video to purchase my cheap folding sharpener:
 
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