Education Workshop
How Ceramic Knives are Resharpened at the Factory

If you’ve ever bought a ceramic knife, it probably came with instructions, in the package, to return it to the manufacturer for resharpening instead of trying to do it yourself. This video is kind of a giant Kyocera commercial, but it does include some cool footage of what this process actually looks like, in case you’ve ever wondered. Turns out it looks somewhat like regular knife sharpening, though I imagine the specific abrasive media in use are different. The good stuff starts around 0:44. And yes, for the safety conscious: as a general rule, in any operation involving a sharp edge, you should probably put it down before adjusting your facemask.

16 thoughts on “How Ceramic Knives are Resharpened at the Factory

  1. And he’s wearing a ring. Jewelry and power tools don’t mix.

    I thought it was interesting that he’s not using a jig of any kind.

    1. Yes, I was surprised too. Either the blades come back with really non-uniform angles, or he’s very skilled. The fact that he almost cuts off his ear multiple times in this video leads me to discount the latter.

    2. When sharpening with a machine you’ll remove a fair amount of material so matching the edge angle perfectly isn’t a big deal, and it also doesn’t make as much difference in food prep.

      When you sharpen probably hundreds of knives day after day you get pretty consistent. It looks like he’s holding the blade completely flat so he just has to keep the edge at the top of the wheel to keep the angle the same.

      As for jewellery, a ring isn’t going to pose much of a safety risk.

  2. Just in case you’ve not seen those before, he’s using Japanese water stones, about 1000 grit for the roughing out and 6000 for the finish, before buffing with rouge. Whether he’s added anything to the water is an open question.

    1. The first one is likely a stone (unlikely to be Japanese because it would wear too quick on a machine) but the horizontal disc looks to be metal, either coated with an abrasive or with an abrasive in the water. The grits could honestly be anything and it’s not really possible to guess just based on seeing it on a video. Also rouge is red, hence the name, chromium oxide is green.

  3. for a long time, i though ceramic knives were “gimmicky”…until i actually tried one! they’re brilliant, as long as you know their shortcomings (ie, they’re brittle, and it’s not a great idea to crush garlic with them or that sort of thing. they don’t flex so much as break.) also, you have to be willing to send them back once every couple years to be resharpened…they stay sharp FAR longer than steel knives, but you can’t really resharpen them yourself, so you’ll probably want a backup knife for the week or so that your Kyocera is out being factory-resharpened. lastly, they’re not exactly cheap, but they’re also way less expensive than a lot of overpriced “famous” chef’s knives *cough* Henckels *cough*.

    i only own a Kyocera mandoline (not knives), but it’s BRILLIANT and wicked-sharp! also surprisingly affordable (i think i paid about $30 for mine.)

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I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

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