SpydercoTri-Angle Cubic Boron Nitride Sharpening Stone with Superior Abrasion Resistance for Professional-Grade Finishing and Polishing - 2-Pack - 204CBN

The Sharkmaker should come with the brown rods and these CBN rods instead of the ultrafine imo. The CBN rods are similar to the diamond rods so be sure to use LIGHT pressure otherwise you will strip the stones right off of the rod in no time but yes they work well and are needed for todays PM super steels such as S30V, M390, XHP etc. without them you will be there all day trying to touch up your edge with just the ceramic rods which is what I like the sharpmaker for, adding micro bevels and quick touchups. CBN rods followed by the brown rods then onto a strop. If I need to do a full sharpening or reprofile I move to a guided clamp system for that but the SM is a great tool for KnifeKnuts. just buy these rods you will thank yourself after the first use.

These work almost effortlessly. Need minimal pressure and can reprofile blades quickly. Just follow spyderco’s directions and you’ll be ready to sharpen your new edge.

Awesome

Just never ever ever never apply pressure to them I mean let the knife fall down them.

I used these rods to re-profile a 1095 high-carbon steel knife blade. Gentle pressure and a little patience worked. This is an aggressive abrasive: it didn’t take as long as I expected. In 15-20 minutes I had the blade reprofiled, honed, and polished (using the rest of the excellent spyderco ceramic rods up to ultra-fine).

Work awesome at first, but great care must be taken to ensure they last for even a short period of time.That is, it takes a great sense of restraint and hand-feel to make sure you don't exert too much pressure on the surfaces of these "stones" as it will simply shear the bonded abrasive grains right off the steel substrate, making them 100% ineffective. Basically, I have learned that at-most you only wanna use the weight of the blade itself to put a steady, even pressure on the stones. These are so abrasive, that this is all you'll really need to re-profile almost any blade...They are a little on the pricey side, so if you don't know how to excerice such restraint, I suggest you look into any of the cheaper alternatives.With that said, they really work great @ removing metal on stubborn blades, even with the exotic super-hard alloys out there today (e.g. ZDP-189, S90V, M4, CTS-XHP, etc...).They seem to perform almost identically to Spyderco's older Diamond Rods...

Get these or the diamond stones if you’re into super steels (high carbide) or like aggressive/toothy low grit edges.These rods make the sharpmaker a complete sharpening system for the majority of knife users though enthusiasts will likely prefer a nicer fixed angle system or stones for free handing.As usual, shipping was quick and the product arrived well-packed with no damage.

Cubic Boron Nitride, it says here, is almost as good an abrasive as diamond. It is preferred for high-speed machining largely because, when hot, carbon from diamond can diffuse into the steel, changing its qualities. So why use it here? I think it’s Spyderco’s “I’ll have one of everything” philosophy. If there’s a material, a mechanism, or a special use for a knife, they want it.I tried these rods head to head with diamond...in fact, using one on each side of a blade. They look exactly alike, but the c-BN rod feels sharper. Even running a finger over the surface there’s a difference. It takes almost no pressure to get it to “bite”. However, the result looks the same--just with less pressure. C-BN crystals fracture more easily than diamond, so the lightest pressure that works sounds like the ticket.I’d expect to see the difference more with a very hard steel, like S110V. But I don’t have one in a knife that needs sharpening, and I’m not willing to sacrifice a factory edge to my sharpening skills.