Metal used that doesn’t need diamond to sharpen

[kobold]

I start with diamonds and end with the UF, then strop. Worked for everything so far.

[Matt Deaner]

I love diamond stones.... Used to use SIC but once I tried a DMT fine I made the switch. Diamond cuts fast so I find it easier to use, since there are fewer strokes hence fewer opportunities to mess up your angle. The flip side is you can really screw up an edge in a hurry if inattentive.

My sequence lately has been DMT coarse, fine (600), xfine (1200), then 1 um paste on wood. This gives a hair splitting edge that still has some bite.

[Murat_Cyp]

I have Chosera and Resin bonded CBN stones. While I can sharpen S90V with Choseras to a very sharp edge, the edge gets noticeably sharper and sticky with CBN stones. Same with S30V. In your case, I do not think you will need a diamond stone with ZDP-189 since it is chromium carbid steel.

I have a method that I follow when deciding about which sharpening stones to use. First, I check the carbide type on the steel. If it is full chromium carbide (or something softer) then Chosera stones are good to go. If it is niobium, tungsten or vanadium carbide steel, then I look to the micrographs of the steel (you can find typical micrograph of the steels on knife steel nerds). Then I check to estimate the sizes of the larger carbides. If the larger size carbides are smaller than my sharpening stone grid, I go with silicone carbide or even Chosera stones. If the sizes of the carbides are larger than my stone grid (usually the case with high carbide volume steels) then I do with resin bonded CBN stones. That being said most of PM steels will benefit from CBN/Diamond stones.

[soc_monki]

From all the reading I've done, the carbides are so small that they just get torn out regardless of the medium used to sharpen, until you get to the 3 micron or less area. Since I never go that far (stopping at Spyderco Fine), I don't need to worry. However, I use diamonds for initial sharpening (220, 320, 1200), and the medium and fine spyderco stones for finishing and touch ups. Tried using strops and IMO (and for my needs) they are unnecessary.

About the only stone I wouldn't use on any of the steels I have are Arkansas stones. I tried, it did not work at all.

[jpm2]

I've never subscribed to the talk that abrasive particles need to be carbide size or smaller to cut them, instead of plowing them out.

If a plated diamond particle is 25 microns, I suspect at least half of it is embedded into whatever has it attached to the plate. Add to that they are tightly packed together, it's possible only 10% is exposed and available to cut. If so, this would reduce the depth and width of cut to 2.5 microns per particle.
A 600 grit DMT fine diamond plate is about 25 micron, according to this grit equivalency chart.
http://myplace.frontier.com/~mr.wizard/GLGC/GLGC.png

For larger grit plates, I suspect as they wear/breakin and the grit gets more of a uniform height, the depth of cut will become much shallower. For instance, once a DMT coarse 325 grit plate, listed at about 50 micron particle size is broken in, its depth of cut might be much less than the carbide size.

I've seen SEM images of 1 micron lapping film scratches on maxamet. The scratched carbides are clearly visible in the images. The carbides are around 1 micron in size and they clearly have a dozen or more scratches side by side on them. This would be in line with 10% or less in width of cut for the given abrasive size. The depth of the scratches also look similar in size.
Unfortunately there are no large grit scratch images. But if there were, I'm confident it would show the carbides being cut, more than plowed.

The images are at scienceofsharp.com if interested.

[MFlovejp]

You can sharpen and maintain any steel Spyderco uses with the standard sharpmaker stones, as long as the edge doesn’t get too dull. Fixing chips or reprofiling though are near impossible without harder abrasives for the harder steels.

[Airlsee]

If I'm just touching up most steels, well any steel I guess, I'll use the double stuff (if the blade is not over 4-4.5").

If I need to do a full re-sharpening, or want to change the angle a little I use the double sided 3 stone 6x1 set from Venev (80-1200grit FEPA F 3centuari). They work really well and have excellent feedback, a little give to them. Plus you get 6 different stones for $100...which is not a bad deal at all.

https://www.gritomatic.com/collections/ ... d-full-set

Somewhere in between those times I use the Sharpmaker 204mf.