Diamond or CBN Rods For Sharpmaker?

Razor

Razor

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Dec 8, 1999
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I have a couple folders in CTS-204P steel. I have read on here that CTS-204P needs to be sharpened using diamond stone to get the full benefits of this steel. For my sharpmaker would diamond or CBN rods be the best? I have the ruby stones for the sharpmaker.
 
I honestly don't think it will matter either way when your talking about diamond or CBN,I think the problem is most people still refer to diamonds as the go to thing because they have been around for so long.
I have purchased straight CBN stones and Venev diamond stones and got a metallic bonded diamond stone from Gritomatic and all have worked really well even on S110v steel witch is what I got the Venev diamonds and CBN for to see witch would work better and both seem pretty equal.

Also the other thing that most people don't realize is that although diamonds are harder then CBN at room temp when diamonds get hot from friction they also get softer then CBN and that's why a lot of big company's from what I have read prefer CBN grinding wheels better for large scale production when using steels that need to be ground down and are difficult to work with.

CBN is the second hardest thing to diamond and it's not much softer at all,I think the thing to remember here is that the CBN is still going to be a good bit hard then the steel your trying to sharpen and that's what you want.I don't think it's really going to matter witch one you choose but if it were me I'd go with the CBN because if the diamonds are just electroplated onto the rods they will just tear off faster then the CBN is going to wear.

The only reason I decided to try the Venev stones is because the diamonds are bonded right into the mixture of the abrasive and they will be anchored in there better,where as with a diamond plate or anything where the diamonds are electroplated on when the diamonds dig into the steel they end up being torn out over time.The Venev stones by the way since I have started using them are still cutting very fast just like when they were new and I haven't seen any sign's of the diamonds being torn out.
 
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Start by reading this thread carefully with regard to sharpening your super-hard steel folders using the Spyderco ceramic rods. There's a ton of useful info in this thread. The basic takeaway: the ceramics in the SM are not the best option for sharpening your super steels, though they will probably work in the short run.
https://bladeforums.com/threads/can-you-use-ceramics-to-sharpen-s30-90-110v-or-not.1519674/

Next, as somebody who's used the diamond SM rods, I wouldn't rely on those, they don't work that great either. They're terrible for any serious metal cutting/profiling work, and they're not even really that great at straight-up sharpening, although they WOULD in fact work on your hard steels. There's no reported significant difference between those and the CBN, performance wise.

Personally, rather than rely on SM to sharpen your folders, I'd upgrade and get a good coarse diamond bench stone. And then get a strop with a diamond or CBN compound to help you maintain the edge you create on the coarse diamond stone. Between a single coarse diamond stone and a strop with diamond/cbn compound, you can do everything you need to maintain those folders. You can always add extra stones and higher grits later if you want to polish your edges more. But a single diamond stone, say a DMT coarse, and a strop with compound, you'd be good to go. You could get a DMT coarse 8" diasharp stone, DMT holder for it, a block of basswood for a strop, and some compound, for about $100.
 
Thanks for all replys. I have a diamond stone I will use and get some diamond paste for my strop.
 
Congress Tools makes stones for tool & die makers. Look in the Ruby section for triangular 1/2" stones. They fit the SM slots are available
in a wide selection of grits & don't scratch the way diamonds do.
 
Agree with the Congress Tools recommendation, if using Sharpmaker, I'd definitely be checking out their different stones including Ruby and MoldMaster. They're really affordable, so easy to get a few and try them.

One caution: the ruby are aluminum oxide, I'm not 100% certain that's going to work great on a super steel like the OP is using. I'd at least call them to confirm that, they might recommend a different stone to try for your steel.
 
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If it were me I'd get the MoldMaker stones as they are Silicon Carbide,but when it boils down to it I would get CBN first then Diamond,I got my Diamond stones and CBN just for using them on my blades made from S110v and nothing else.
 
maximus83 said:
Agree with the Congress Tools recommendation, if using Sharpmaker, I'd definitely be checking out their different stones including Ruby and MoldMaker. They're really affordable, so easy to get a few and try them.

One caution: the ruby are aluminum oxide, I'm not 100% certain that's going to work great on a super steel like the OP is using. I'd at least call them to confirm that, they might recommend a different stone to try for your steel.
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Get the mold masters like suggested here ^

They will work fine for cts204p and are very low cost. SiC is good stuff. Diamond and cbn rods are fragile.
 
Mo2 said:
Get the mold masters like suggested here ^

They will work fine for cts204p and are very low cost. SiC is good stuff. Diamond and cbn rods are fragile.
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So the Moldmaster triangular stones fit in the Sharpmaker?
 
Tyrolit also has 13x150 AlOx (fine/medium) and SiC (fine only) triangles which should fit.
 
Until Spyderco comes out with more improved SM rods in a range of grits for maintaining super steel blades, users need to figure this out for themselves. I'm not much into using SM anymore, mostly doing freehand, but interested in trying the Congress Tools stones to use SM just as a maintenance strategy for super steel blades. Called and spoke to one of their reps this morning, then ordered a couple of their stones as below to try this out. If the results are worth mentioning, I'll post back to maintenance forum later.

  • For Sharpmaker primary sharpening stone option for super steels: I order a few grits of the Congress Tools silicon carbide Moldmaster 1/2" triangle stones. These are super inexpensive (around $4 to $6 each), so I ordered 240, 320, 400, and 600 to try. They have lower grits too, but I don't think SM is great for trying to profile blades, so I didn't bother with the lower grits. My use for these grits would be a range of sharpening tasks from minor to moderate edge repair, up thru apexing. 600 grit is the highest option in the MoldMaster series. The rep agreed that in their entire lineup, for sharpening super steels, the Moldmaster SiC stones are the way to go, and that you'd not want to use the Ruby stones, or any of their other stones, as your primary sharpening stone on super steels. Key attributes I'm looking for in these SiC stones, versus the Spyderco diamond/cbn stones: better cutting efficiency, AND a smoother sharpening surface and sharpening experience, which would make it possible to better maintain a consistent edge and scratch pattern while sharpening.
  • For Sharpmaker finishing stone options for super steels, will try 2 options:
    • The Congress Tools Flex stone, in 600 grit, which is the highest grit available in this stone series. The rep suggested this as a polishing/finishing type of application only, and said that if I was interested in trying something they have as an alternative to the Spyderco ceramics, this would be the one to try. And he's sold it to a few other pro knife sharpeners who have used it. I wish the grit were a little higher, and I think the issue remains that these stones are "hard aluminum oxide with a resin bond." They are not optimal for finishing super steels, diamond or cbn would be, but we have no Spyderco Sharpmaker compatible offerings of this type in a high grit. This stone was only $7, so I added it to my order and will check it out.
    • The Spyderco Ultrafine ceramics. Again, not optimal, but these DO seem to work to refine an already sharp and apexed edge on super steels like S30v and S35vn. I tested this with my UF rods just last night. About 5 super light strokes per side, after apexing on bench diamond stones, and it did get these blades noticeably sharper. So, lacking a high-grit diamond/cbn stone to finish super steels in the SM, perhaps the UF stone is an ok fallback option.
 
I'm going to order those too at some point. The thing with SiC is that they will wear much faster and also dish.

So I assume you may want to get a stone flattening kit of some sorts. Keep them flat as possible. Not sure if they need to be flattened from anew.

Also they are shorter than the standard rods. Not a problem for me, just letting others know.
 
maximus83 said:
The Spyderco Ultrafine ceramics. Again, not optimal, but these DO seem to work to refine an already sharp and apexed edge on super steels like S30v and S35vn. I tested this with my UF rods just last night. About 5 super light strokes per side, after apexing on bench diamond stones, and it did get these blades noticeably sharper. So, lacking a high-grit diamond/cbn stone to finish super steels in the SM, perhaps the UF stone is an ok fallback option.
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https://www.bladeforums.com/threads/can-you-use-ceramics-to-sharpen-s30-90-110v-or-not.1519674/
 
^I already linked to this thread earlier, and am basing part of discussion here on it. So what's the point?

Using ceramics--AT ALL--on super steels is disputed. Some folks think it's fine, some don't. That's the whole point of that other thread. Here, we're talking about folks that are determined to use SM for super steels, so the point is if you're going to use SM anyway, how do you make the best of it with the available rods.
 
Mo2 said:
No point just referencing that thread. Didn't read above. My bad.
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Yep, understood. To be completely transparent: I don't KNOW whether using ceramics to finish, as suggested above and linked in that other thread, is actually a good sharpening strategy. And I'm not sure anybody really does. Some knife-making or sharpening pros will have more extensive observations from what they've tried, that is really useful data, but the problem is some of them are reaching different conclusions. :) From observation, it just seems like everybody tries stuff, and then you go and do what works, and people end up with different methods. :) All I know is, as in that linked thread, I tried last night the approach of super light finishing passes on an already apexed super steel. It SEEMED to make the edge even sharper. But some sharpening pros in that thread are saying those results could be deceiving. On the other hand, you have some fairly reputable people--like Cliff Stamp, and Sal Glesser--who believe that refining a super steel on a ceramic works just fine, no problem. So, the jury's still out I think on the use of ceramics even to finish on a super steel blade. Planning to keep experimenting with it for a while and see how it goes, versus just finsihing on diamond stones.
 
Some threads at Spyderco forums are relevant to this discussion. It wasn't talking specifically about super steels as the OP is, but the question was how to incorp the diamond/cbn rods into your sharpening strategy. Linked below are several threads that have interesting info about all this, including comments from Sal Glesser, Cliff Stamp, and others. And Cliff's testing results on CBN. Lot of interesting info in there, for folks trying to understand the various options that you have on Sharpmaker, and how to get the most out of your Sharpmaker.

One interesting comment that Cliff made in a thread, based on his testing, on how to use the CBN together with the other SM rods. Sal jumped in later in the thread and recommended Cliff's approach. The relevance here in this thread: as above, it COULD be a valid approach to try to use your diamond, CBN, or (in my case) aftermarket SiC stones like the MoldMaster, to do your apexing, and then use the Spyderco F or UF ceramic rods for just a few very light passes to finish. If you agree with Cliff, and Sal, that ceramic is a legit option to finish/refine a super steel blade after apexing. There are many here who do not agree with that. Me, I'm trying to make up my mind by just trying the approach and see what happens. :)

Apex on the diamond rods, do just a couple of passes on the medium rods - check the edge. The more passes you do the closer it will come to the medium rod finish. By varying the number of passes you can generate an edge which has the essential behavior of any grit between the two.
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https://www.spyderco.com/forumII/viewtopic.php?t=66087
https://www.spyderco.com/forumII/viewtopic.php?t=63254
https://www.spyderco.com/forumII/viewtopic.php?t=68482
http://www.cliffstamp.com/knives/forum/read.php?10,26465
 
I'm sure this video is already linked in one of those threads but to help anyone who chooses the cbn or diamond stones here's cliffs video to do it the correct way to not damage the rods.

 
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