Ceramic Blades?

[TomAiello]

Has Spyderco ever made a ceramic blade knife?

I've been using a folding ceramic blade as the "small, precise, sharp" knife in a two knife EDC set (the other is a Manix XL). It's really been outstanding in this role. Super sharp, stays sharp well, and I can touch it up with the stropping belt on my worksharp.

I'd love to see something like a DragonFly 2 with a ceramic blade.

[Liquid Cobra]

I remember reading something Sal said about ceramic blades. I think they tried, but it was tough to work with or something like that. With a company like Spyderco you can bet it its sharp, they've worked on it or will.

[Cliff Stamp]

Tom,

Sal has noted they had worked with it, issues with sharpening/sharpness.

How sharp is the blade you are using, comparable to a as-boxed Spyderco typical steel? Is the stropping belt you used loaded with some compound?

[TomAiello]

It's the stropping belt that came with the WS. I haven't done anything else to it.

The ceramic blade started out with a (totally subjective) sharpness exceeding my out of the box Manix 2 LW s110v. I think that the only knives I own that came sharper than this from the maker are my two Phil Wilson customs.

[The Deacon]

There has never been a production Spyderco with a ceramic blade. However, while neither were "Spyderco branded" items, back in the early 90's when Spyderco was acting as a US sales agent for a number of their Japanese suppliers they sold a small ceramic bladed folder made by Tak Fukata and a pair of ceramic bladed fly tying scissors made by G Sakai.

[VashHash]

One of the members here has some some extensive sharpening of ceramic kitchen knives to the point of full polished edges. Very beautiful stuff but if you drop the folder it's not good. With the current super steels offered I'm not interested in ceramic personally. I'd rather see K390 in a folder or fixed blade before ceramic.

[zhyla]

The novelty of ceramic blades wore off pretty quick for me. I have a couple Kyocera kitchen knives and one Kyocera folder. The kitchen knives worked ok but chip easy and don't have enough weight to them. The folder was more of a wedge than a knife, the geometry necessary to keep it from chipping in an EDC role is ridiculous.

It's probably not doing good things to your strop either.

[Blerv]

Since there isn't really a comprehensive sharpening option for ceramic knives from Spyderco (not with the 204 Sharpmaker kit at least) I don't think they will head in that direction.

Some of the steels they are experimenting are getting close to the ceramic range of performance while remaining more tough/ductile (for durability and restorative purposes). I'm sure for some things ceramics/glasses will still have merit over steel but for a market of people who accasionally hit staples and drop knives I'll remain cautiously optimistic for it's retail future in pocket knives.

[Cliff Stamp]

Some of the steels they are experimenting are getting close to the ceramic range of performance while remaining more tough/ductile (for durability and restorative purposes).

If by performance you mean how the knife would perform in a CATRA style comparison then ceramics are further ahead of steels like 10V than 10V is than 420J2 in the same type of comparison.

[TomAiello]

It's probably not doing good things to your strop either.

The stropping belts aren't very expensive, and I have several more, so I'm not too stressed about that. It's working for now, at least.

[Blerv]

Some of the steels they are experimenting are getting close to the ceramic range of performance while remaining more tough/ductile (for durability and restorative purposes).

If by performance you mean how the knife would perform in a CATRA style comparison then ceramics are further ahead of steels like 10V than 10V is than 420J2 in the same type of comparison.

Interesting Cliff. I didn't know that.

There is a question of how to work with them though. That's perhaps more a tool design question than an ability one though. Long ago the idea of hybrid vehicles scared technicians in the same way fire scared cavemen.

[Cliff Stamp]

There is a question of how to work with them though.

They can actually be ground with regular abrasives. A few years back I had a friend drop off two very inexpensive ones, broken tip, really torn up edge. I resharped them with a basic alumina belt. Now of course what was happening was similar to using one stone to flatten another, they both just wear against each other really fast.

The only concern I would have is in sharpening, not shaping. Shaping is really easy, just get a really coarse stone, ideally with a soft bond. But actually getting them sharp is really not trivial because :

-the grindability is really low
-they don't burr form (so that entire method is out)
-they grind by fracturing/chipping

I have played with them a few times and have had no success with getting them sharp off of course stones, the apex just fractures on the micron level. Now to be clear I am not talking about slicing newsprint, that's easy, but that really isn't what most people judge when a steel knife is sharp.

Get a decent as-boxed sharpness from Spyderco and it will catch the hairs above the skin, cut newsprint with no draw, all of those fun things. Getting that with a ceramic blade needs really high grit diamond/cbn abrasives. Now these are available in sandpapers, it isn't impossible but just work with one and look at how trivial it makes sharpening steel in comparison.

However this can be greatly mitigated if you :

-high precision jig sharpen (edge pro, WE) and have the necessary stones
-power sharpen and have the necessary buffing compounds

If you go on YT you can watch people sharpen ceramic blades on power equipment in just a couple of minutes. Ceramics like alumina and even the really fancy high strength ones modern blades are made out of are still butter soft compared to diamond.

[kwakster]

Currently reviewing this ceramic kitchen knife:

http://www.bladeforums.com/forums/showt ... amic-knife" onclick="window.open(this.href);return false;

as well as this titanium hybrid kitchen knife from the same manufacturer:

http://www.bladeforums.com/forums/showt ... fe-GHT-16-(Cera-Titan" onclick="window.open(this.href);return false;)?highlight=titanium+hybrid

[SpyderEdgeForever]

This topic greatly interests me. I have studied ceramics for years and I am glad to see greater interest in ceramic bladed knives and cutting tools. I concur with Cliff on this. I would like to see more widespread use of boron nitride and reinforced ceramics of assorted types for knives. Perhaps a good transition, if possible, would be a ceramic-metal compound that has some of the plastic deformation properties of metal for stress concentration, but, also provides the hardness and durability and corrosion-resistance of the ceramic portion.

[Cliff Stamp]

As a point, the sharpness demonstrated here would be decent even for steel blades which demonstrates in an absolute sense there is no issue with ceramics and sharpness.

https://youtu.be/q4YGGHltloU

However from a practical argument it is different.

[Cliff Stamp]

... if possible, would be a ceramic-metal compound that has some of the plastic deformation properties of metal for stress concentration, but, also provides the hardness and durability and corrosion-resistance of the ceramic portion.

That is exactly describing steels.

Take for example ATS-34, it is mostly martensite which provides the gross properties (strength, toughness, corrosion resistance) and it has ceramic particles (the carbides) to enhance the wear resistance and to a lesser extent, strength in compression.

Move way up to 121REX, the amount of ceramic has increased vastly so it is starting to move towards the properties of sintered ceramics.

There are even other alloys which push the carbide fraction up even higher, for example there is a CPM-20V :



and there are extreme adhesive wear "steels" which have just absurd levels of carbide and carbonitrides :

-2% Carbon, 10% nitrogen, 30% Chromium, 14% Vanadium/Niobium

Even beyond that there are metals made, often through powder processing to add reclaimed carbides to enhance the carbide fraction of the metals to extreme levels, ~50%

[Fancier]

Actually, I do think that slicing newsprint is how most people judge if a knife is sharp...

[Cliff Stamp]

Actually, I do think that slicing newsprint is how most people judge if a knife is sharp...

In that perspective then getting a ceramic blade sharp is pretty trivial, even more so than steels as they don't readily burr. All you have to do is just grind an apex with even a $1 no-name diamond stone. Even if you over grind it won't tend to readily burr.