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Can ceramic knives be sharpened?

josephnl Nov 19, 2010 02:22 PM

I was just looking at an ad for Kyocera ceramic knives that look pretty nice. The ad stresses that they retain their sharpness for a "long time" and they are warranted for five years (? for retaining sharpness??). Does anyone have any experience with these knives? Can they be sharpened at home? by the factory? or, not at all?

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  1. d
    dscheidt RE: josephnl Nov 19, 2010 03:24 PM

    The factory can do it. A very skilled sharpener with very fine diamonds can do it.
    I think ceramic blades make sense for a limited number of purposes, and kitchen knives aren't among them.

    1. Chemicalkinetics RE: josephnl Nov 19, 2010 03:58 PM

      Very tough, both because they are hard and because they are brittle.

      1. j
        jmnewel RE: josephnl Nov 19, 2010 04:08 PM

        I bought one (chef's knife shape for chopping) about 10 years ago. Loved it for certain things for about 2 years, then noticed it wasn't doing the job so well. Sent it to the factory for sharpening (it was an easy process) and it was good for another 6 months to a year. These are expensive knives. I wouldn't recommend that anyone buy one for general kitchen use. It was a joy when it was new, though.

        1. Caroline1 RE: josephnl Nov 20, 2010 03:52 AM

          You can do it at home. Kyocera says so::

          1. cowboyardee RE: josephnl Nov 20, 2010 05:07 AM

            More often than not, the factory will sharpen a ceramic knife for a fee. You can decide if the fee is worth it. Realistically, that's usually your best bet (that or buying a new one - prices have fallen).

            The electric sharpener Caroline1 linked above might work. I dunno. It's not a well known product and I haven't seen any especially credible reviews of it.

            I haven't tried to sharpen a ceramic knife, and truth is I probably wouldn't unless I had one sitting around that I didn't mind possibly making worse as well as some diamond stones.

            From what I've read though, it is possible to do at home - with diamond stones. Possibly even with wet/dry sandpaper. There are several problems though - I've heard that a coarse DMT will usually take chips out of the edge, meaning you're limited to fine grit. You also should probably refrain from using much pressure for the same reason. This means it might take a long while. Also, you shouldn't expect a burr to form, which might be a problem if you (or whoever, since this is clearly addressed to people already familiar with hand-sharpening) rely on finding a burr to know when you've hit the edge.

            Even then, I couldn't guarantee it would work. Dave from DR sharpening claims to have had success with hand sharpening ceramics like this though.

            Thing is, if you're willing to hand sharpen in the first place, you may as well get yourself a nice traditional knife and just keep a fine edge on it.

            3 Replies
            1. re: cowboyardee
              Chemicalkinetics RE: cowboyardee Nov 20, 2010 03:30 PM


              Excellent feedback as always. Yes, these are my impression as well. Diamond stones should be one of the few tools for sharpening, but coarse diamond stone surely will crack or chip the ceramic.

              1. re: cowboyardee
                sewercat RE: cowboyardee Jun 4, 2014 11:42 PM

                I hand sharpen everything and have done so for years (an electric sharpener ruined the finish on a really nice SOG knife I had and I've been wary of them ever since.) There are basic problems with hand sharpening that a good ceramic addresses:

                First is time. I hand sharpen semi weekly and use a basic steel daily to keep the edge on a steel knife. They'll cut tendon and butter equally but it takes time and attention to angles to maintain that.

                Second is cleaning. Every time I sharpen a knife I have a stone to clean, oil to wipe up and a blade to clean. steel dust gets everywhere and the last place I want it is my food. i sharpen steel knives either weekly or every 2 weeks if I'm busy.

                I sharpen my ceramic knives on a diamond stone bi-montly and they're just as sharp as the steel, if not sharper (on average)

                I use a fine/medium diamond stone by RedHead that I picked up at Bass Pro and it's kept my ceramic knives in fine condition without chips

                1. re: sewercat
                  Cynic2701 RE: sewercat Jun 6, 2014 09:02 AM

                  I sharpen with 4000it grit Shapton Glass waterstone every other week. It takes 45 seconds, and all I have to do is wipe up water and slurry afterwards--which takes 10 seconds. Every couple of months I'll break out a 1000 or 2000 Shapton Pro to thin behind the edge, but it doesn't take much more than 3-5 minutes per knife. If you have time to cook, you have plenty of time to sharpen. You can whittle hair with the edges I get off of the stones, and I haven't even stropped with compound.

                  I've only ever had issues with steel dust with diamond stones.

              2. k
                KingoftheCastle RE: josephnl Nov 20, 2010 09:56 AM

                I just send them back to Kyocera for a good sharpening. Nice and easy..

                1 Reply
                1. re: KingoftheCastle
                  josephnl RE: KingoftheCastle Nov 20, 2010 02:54 PM

                  Do you like them, and how would you say they compare to a good stainless knife?

                2. bgazindad RE: josephnl Nov 20, 2010 12:40 PM

                  I have a ceramic knife and I sharpen it with little kit I bought in West Los Angeles. It cost about $15. I really do not know the name of the product since the packaging is in Japanese except the word forever and diamond. Its easy to use and does the job. I had an electric sharpener that I got in Japan but it wore out.

                  1. p
                    pabboy RE: josephnl Nov 21, 2010 09:40 AM

                    Yes send it back to Kyocera to be sharpened. The blade is very brittle so if if you are rough on knives like me, i.e. drop on counter or into sink, then it's not for you. That said, it's very sharp and stays sharp longer than any of my other knives. If you use it on regular basis then you will need to send it back every year or 2 to be sharpened.

                    1. n
                      Nugentrocks RE: josephnl Dec 4, 2010 09:37 AM

                      I have one and I'll Give it away. Terrible3 as far as I'm concerned.

                      3 Replies
                      1. re: Nugentrocks
                        josephnl RE: Nugentrocks Dec 4, 2010 09:35 PM

                        What are you talking about? Is it a Kyocera ceramic knife that you think is terrible...if so, why?

                        1. re: josephnl
                          Nugentrocks RE: josephnl Dec 5, 2010 09:22 AM

                          Yes it is. It seems to wedge and it wasn't that sharp when I got it too.

                        2. re: Nugentrocks
                          sewercat RE: Nugentrocks Jun 4, 2014 11:46 PM

                          it's been a couple years. Am I too late to get a free Kyocera knife?

                        3. r
                          RickyP03 RE: josephnl Dec 11, 2010 11:37 AM

                          I brought one from the infomercial at Walmart. I was first concerned with what NOT to use it on. Meat wih bones, type on cutting board, etc. I used it for about 3-4 months and it started getting not so sharp and was lookinh for how to resharpen it. Then will washing it I dropped it on the hard tile floor and it broke. As one person indicated, ALL knives get dull...if you use them. I've had $200 knives all the way down to the $1 knives at Dollar Tree; Fromm Miracle Bale and the like; and they ALL got dull Get a $10 hand sharpener from the hardware stare and visit Dollar Tree...you'll come out better..

                          1. Fuboon ceramic knife RE: josephnl Dec 22, 2010 07:00 PM

                            ship back to sharpen is the best choice,their knife is expensive,why not try other brand ceramic knife with high Cost-Effective? ...

                            1. Candy RE: josephnl Dec 22, 2010 08:30 PM

                              Kyocera will sharpen your knives for free and send them back to you on their dime. Most Kyocera knives need sharpening about every 18 mos. If you do have a diamond hone or "stone" you can do it yourself. You need to know that Asian knives have a blade angle of 15 degrees as opposed to western knives which are 20 degrees. Unless you are skilled at sharpening, it is better to send them back to Kyocera in Calif. They ahve even replaced some broken knives for free, even when the breakage was due to operator error. One one of my favorite Kyocera is the micro serrated knife. It is wonderful for soft fruits and vegs. Slices through them like butter.

                              1. TonyC RE: josephnl May 31, 2013 11:55 AM

                                updating after almost 2 years of ownership. i held out getting it sharpened since kyocera asks $10 for "free" sharpening. ended up sending it back on a "warranty" claim since there were small chips up and down the blade. 9 months after sharpening, i had to send it back again. we don't have bamboo cutting board, and have enough knivse to not use this to breakdown chickens, etc. not sure if this means we're "hard" on knives, but it's a ridiculous. the new 4" pairing knife was only $20, but this shipping back and forth borders stupidity, even if i'm located in the same state as the kyocera service center.

                                ironically, the current main cook in the house has fallen in love with it, and i have no choice to keep sending this damned POS back to Costa Mesa every 9 months or so.

                                4 Replies
                                1. re: TonyC
                                  Chemicalkinetics RE: TonyC May 31, 2013 02:20 PM

                                  < the current main cook in the house has fallen in love with it,>

                                  There may be some reasons for the love. You can sharpen your ceramic knives on your own, I read, but it will take some skills.

                                  1. re: TonyC
                                    pearlyvictoria RE: TonyC May 10, 2014 03:22 PM

                                    I hope you purchased a new one bynow. They are not that expensive these days. The reason I am here is because I have one that is 4 years old and just wanted to see what my options are before I toss it.

                                    1. re: pearlyvictoria
                                      wabi RE: pearlyvictoria May 12, 2014 12:23 AM

                                      If you read the posts closely you will notice they say..."oh yes, you can do it yourself...but it takes some skills or time or diamond stones.

                                      Are you adept at sharpening your own conventional knives?
                                      Do you possess the right equipment?

                                      See...it can be done...BUT...........

                                      Save yourself some trouble, If you have one, send it in to Kyocera. Let the pros work on it.

                                      My wife loves her Kyocera ceramic knife, which is good, because it keeps her away from my carbon steel Takedas and Carter knives.

                                      1. re: wabi
                                        sewercat RE: wabi Jun 5, 2014 12:04 AM

                                        It's not hard. I learned when I was a kid. Buy a diamond stone ($20) Angle the knife right (15 degrees for Japanese knives, 20 degrees for anything else, (use your finger to judge- I use a thumb for 20 and a finger for 15 and check that the original edge closes to the stone cleanly. push it down the length of the stone and the knife so that the very tippy tip slides off the corner of the stone. Repeat 4-10 times depending on initial sharpness.

                                        Flip and repeat drawing towards yourself. use a guard of some sort if scared.

                                        check the burr- it will probably feel sharp drawing against the most recently sharpened edge. Draw the opposite edge until burr subsides. Check opposite edge. repeat…. opposite. repeat opposite repeat oppose.. just do it until the edge sinks into your fingernail enough by weight of the knife by itself that it sticks in place by its own weight if you try to slide it down your fingernail

                                  2. b
                                    Bunson RE: josephnl May 13, 2014 09:37 AM

                                    I got a Kyocera ceramic knife but had to toss it after I accidentally chipped it. They look pretty and make a nice conversation piece but I think steel knives are more practical.

                                    1. C. Hamster RE: josephnl May 14, 2014 11:56 AM

                                      Kyocera sells a home sharpener

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