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May 21, 2011 02:58 PM

CarboNext Santoku Quick Review

As indicated from a previous conversation ( ), I was considering to purchase a stainless steel Santoku. At the end, I bought the JCK CarboNext Santoku which is a carbon steel knife. First, let me say that I am extremely impressed by Koki Iwahara's delivery speed. I ordered on May 17th, 8:00PM, Koki shipped out my knife within 3 hours, and the package was attempted to deliver to me on May 20th. I wasn't at home, so I picked it up today on May 21th. This is fast for a shipping from Japan.

As shown in the first photo, the CarboNext Santoku (bottom) is placed next the Tojiro DP Gyuto (top). The Santoku is a shorter but wider knife. Its fit and finish is fine. The handle is dark brown and it is rounder (less boxy) than the Tojiro. The edge profile is more curved than I would have wanted. In the second photo, you can see that CarboNext Santoku (top) curves up about the same as the Tojiro DP Gyuto (bottom). The photo may actually shows the Santoku more curved, but I double-checked, they are the nearly the same. The factory grind is indeed asymmetric as advertised. It is asymmetric with different angles. In other words, it is #4 in this following picture:

The factory edge was fine. It sliced meat just fine. It shaved my arm hair at least from one side of blade and could push cut on printer paper -- though not very smooth.

I reprofiled the knife with a final ~10o symmetric grind. It was not too difficult to sharpen, and burr formation was easy. After completion, the new 10o edge could better push cut paper. I sliced off some more pork shoulder meat. It appeared the edge was duller after the light task, but could still shave my arm hair and push cut paper – it just felt less smooth. The knife can stain/oxidize a bit, but it is very faint. It indeed has good rust resistance for a carbon steel knife. This is my very first day experience with the knife. So far many of the rumors have been proved to be true. The edge retention is not as good as I had hoped for, but I did reprofile it all the way down to 10o. It is very possible that 10o each side is too acute for this knife. I will most likely bring it back to 15o like my Tojiro knife. I know my Tojiro also had troubles holding the 10o edge angle. I will have to play around with this knife for 2 more weeks to get a better feel. So far, it seems to be on par with a VG-10 knife. It does not seem to have the same hardness and edge retention as my Tanaka Aogami Nakiri.

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  1. Very nice Chem! The carbonext was on the top of my short list for my next eventual purchase - a sujihiki.

    I have to run so I can't post too many questions. But my big ones are:

    How long have you had it, and how have you thus far tested its edge retention?

    How does the grind compare in overall thickness and thickness behind the edge to, say, your tojiro DP gyuto?

    How are you liking the santoku profile as compared to your gyuto and nakiri?

    Thanks for the review.

    10 Replies
    1. re: cowboyardee

      Congrats doctore!! :-D Very nice indeed.Have you tried putting a micro bevel on any of your knives?
      It might help with edge retention, from what I've heard.

      1. re: petek


        "Have you tried putting a micro bevel on any of your knives?"

        I may just do that if I don't think the 10o is suitable for this knife. So when I put the 15o back, then it will be very similar in putting a micro bevel. In general, I don't put microbevel. I had in the beginning, but I stop doing it. This because I thought putting a simple profile is easier. I just do 10 or 15 edge on my knives. Putting Microbevel means I have to put extra time for sharpening, and every time I resharpen my knives, I will have to take down more metal because of the microbevel.

        1. re: Chemicalkinetics

          Jon from JKI has a great youtube video on micro bevels,plus other great videos as well.

          1. re: petek

            :) By the way, I am not super familiar with JapaneseKnifeImport. I have visited its website a months back. Maybe 4-6 months ago. Do you know what is JKI's nitch? I mean Chefknivestogo goes for massive selections of all knives with (more) affordable prices. JapaneseChefsKnives goes for authentic and higher end Japanese knives. What sort of space is JKI trying to etch out?

            1. re: Chemicalkinetics

              JKI is definitely all about "authentic" high end knives.He carries some beautiful knives and his videos are very informative.But enough about JKI. 3 days shipping from Japan is unbelievable.Did you have to pay duty + shipping? I'm not sure how it works south of the border.

              1. re: petek

                No, I definitely did not pay for customs duty. The Santoku was listed as a $100 knife with a $7 shipping fee. Yeah, more like 2.5 days shipping from Japan really -- just as fast as any domestic shipping.

                1. re: Chemicalkinetics

                  Nice! Enjoy your new knife and keep us updated.I'm so envious right now.

      2. re: cowboyardee

        "I have to run so I can't post too many questions."

        Baby Cowboy calling you?

        "How long have you had it, and how have you thus far tested its edge retention? "

        Just picked it up today and have it for a few hours. It felt duller after I sliced off some pork shoulder meat which is a very light job. By edge retention, I meant the edge retention at the 10o edge angle. Maybe it is too acute. I know my Tojiro DP also had problems at that low of an angle.

        How does the grind compare in overall thickness and thickness behind the edge to, say, your tojiro DP gyuto?

        The spine of my CarboNext Santoku is thicker than my Tojrio DP Gyuto, but the CarboNext narrow/thin down fast and appears to have a slightly thinner "behind the edge" than the Tojiro.

        "How are you liking the santoku profile as compared to your gyuto and nakiri?"

        In term of the edge profile from tip to heel, I like the nakiri because it is straighter. In term of the grind, I like the CarboNext as it is fairly thin and very uniform. None of that "wavy edge" problems.

        Edited: Just realized some of our "standard" are very skewed compared to most people. I just realized that I described the CarboNext Santoku getting dull when I also said it can still shave hair and push cut paper. I think I just have to play around with it for another week or two.

        1. re: Chemicalkinetics

          Great looking knife Chem, 3 days from japan is unreal for 7 $. I'm in a rush but I know what you mean that it doesn't "feel" as sharp even though it shaves and push cuts the same , I've had the same experience going from 10o to 15o and now I'm at 18.5 trying to get rid of the chipping. It will take time to get used to the new angle.

          1. re: Dave5440


            Yes, I was "charged" for US $7 for the shipping and handling, but I bet it is more in reality. The reason is that mail package states that the postage fee was 1500 Yen which is about US $18. So I think Koki simply incorporated some of the shipping cost into the listed sale price. Nevertheless, the important thing is that you won't have to pay much more than the listed price you see on JCK website.

            I put a small microbevel at 15o last evening. The edge feels more stable now. I will have to test drive it some more.

      3. Hey Chem,

        Nice acquisition! Is this your 1st santoku? The blade looks appropriately curved to me; it is a multi-purpose knife after all. Why do you wish the edge was straighter? Wouldn't that make it more like a jumbo nakiri?

        I'm definitely interested in your impressions after a few weeks of use. Have fun playing with it!

        1 Reply
        1. re: Eiron


          Technically, it is not my first Santoku. My mom gave me a Santoku when I attended college, so a Santoku was my very first kitchen knife. I don't remember much of it. It wasn't not a bad knife, but I don't think it was a good knife either. Come to think of it, the curvature of this knife is not too bad. As stated, it is just as straight/curve as my Tojiro gyuto, which means it is straighter than a typical German Chef's knife. I will have to play with it a bit more. Will update after playing with it for a week.

        2. One week upate.

          I have received and used the CarboNext Santoku for one week with four cooking preparations. The CarboNext knife edge has become much more stable after I brought the edge angle from the 10° to 15°. The overall edge retention is better than my Tojiro DP knife. It did have trouble holding the edge at a low angle of 10° as mentioned before, so I don’t think its edge retention at low angle is not as good as an Aogami (blue paper) steel knife. Its overall grind is uniform along the edge, just like my Tojiro. There isn’t any over or under grind area. It behaves much like a stainless steel. It has developed a faint of discoloration area, but faint. As long as you wash and clean your knife by hands (as opposed using an automatic dishwasher), it really behaves more like a stainless steel knife than a carbon steel knife.

          I like the knife a bit more so than my initial experience.

          25 Replies
          1. re: Chemicalkinetics

            Thanks for the update.

            I'm glad you're liking the carbonext a little more now. I was halfway to taking their suji out of consideration for my next knife purchase based on your disappointment.

            The edge retention on these things is talked up so much that I wonder how it would compare to Aogami steel when both are at 15 deg. It may be the case that for whatever reason (probably grain structure) the Carbonext's steel just doesn't support a very low angle edge but still has superior edge retention at moderately low angles. Or it may be the case that all the hype about its edge retention was just that - hype.

            I'm still wondering how you find you like using a santoku over time. Do you think it will push another knife out of your most used rotation?

            "Its overall grind is uniform along the edge, just like my Tojiro"
            Do you mean that the thickness is pretty even behind the edge for the length of the knife? The Tojiro seems not to have a very pronounced distal taper until the last inch (or less) at the tip. Are you referring to this or are you just referring to there being no poorly or sloppily ground areas on either knife?

            1. re: cowboyardee


              I only read bits and pieces about the CarboNext. Something about it has superior edge retention and stainless-like property, right? To be honest, I don’t really know exactly details of the hype. I also read speculations that CarboNext knives are the same as Kikuichi TKC knives. If so, CarboNext knives are much cheaper.

              I suppose edge retention can be different things in different situations. I read that my Tanaka Aogami #2 knife is tempered at a fairly high HRC (speculated at HRC 64), whereas the CarboNext knives are hardened to HRC 59-61 according to JCK website. So, I suppose it is not surprising that my Aogami knife can hold a lower angle edge (10°) without less rolling or collapsing. On the other hand, the CarboNext knife definitely has better corrosion resistance (more stainless). Who knows? It may also have wear resistance (resistance against abrasion).

              I think I described the grind in a poor fashion. I wasn’t trying to talk about the distal taper. I was trying to say that the grind along the edge is smooth. There is no over-ground area or under-ground area, and therefore no “wavy edge” described by Dave Martell. That is probably expected for a mass production knife.

              1. re: Chemicalkinetics

                It may just be that the carbonext has excellent retention FOR a mostly stainless knife that line cooks can bring in to work without babying it.

                I hadn't heard that it was the same as the TKC, though I did hear that it's similar. I'll see if I can find more info when I have more time (yes, both work and babycowb have been eating up my time). The TKC gets lots of love, as you probably know. Though I haven't used or sharpened either.

                You didn't describe the grind poorly - you just threw me with the comparison to Tojiro, which I read to mean more than it did, since the Tojiro grind is a little different than that of many gyutos.

                1. re: cowboyardee

                  "you just threw me with the comparison to Tojiro, which I read to mean more than it did"

                  I was comparing the CarboNext knife to the Tojiro DP and the Tanaka Aogami. At that particular moment, I was trying to say that grind is proper like the Tojiro, and UNLIKE the Tanaka. You may remember that the grind on my Tanaka Aogami was not great. I had to even out the edge section because there were over and under-ground areas -- what Dave Martell describes as wavy edge. The uneven grind wasn't really horrible, but it was there for sure.

                  Yeah, I read bits and pieces about TKC, but really don't know that much about it.

                  I wish I have a babycow.... although mine won't be called a "babycow".

                  1. re: Chemicalkinetics

                    Hey Chem,anymore updates on your CarboNext? You still lovin' it? Any plans for future purchases? Maybe a suji.. :-D

                    1. re: petek

                      Still loving it. Originally, I had some reservations because it couldn't hold an edge at ~10° for long, but once I bought it up to ~15°, it does a pretty good job. The CarboNext edge feels slightly better than the Tojiro DP VG-10.

                      Although it is a carbo steel per se, I like to compare it to those cladded VG-10 knives like the Tojiro DP. Think of it like a Tojiro VG-10, but being a tiny but easier to sharpen and takes on more of a "bitting" edge. It is very "stainless" for a carbo steel knife. Don't get me wrong, it does discolor slightly, but it definitely does not rust like a Shirogami knife.

                      Sujihiki? Do you eat a lot of fish?

                      1. re: Chemicalkinetics

                        I do eat a lot of fish,but I don't own a Sujihiki :D . I thought maybe you might want to add to your collection(nakiri,gyuto,santoku)

                        1. re: petek

                          The suji will be my next eventual purchase, though I'm still undecided as to brand.

                          1. re: cowboyardee

                            270mm,300mm or the big gun 330mm? SS or carbon? I can still get by most slicing jobs with my 240mm Moritaka,the profile is so slim it kinda looks like a suji.

                            Maybe one day....So many knives to choose from and not enough time,or money.

                            You and chem are so lucky to have so many online retailers to chose from down there in the U.S. of A.

                            1. re: petek


                              I came back from a conference and there I met my old friend from my old graduate school. She said everything is more expensive in Canada, including scientific instruments.

                              1. re: Chemicalkinetics

                                She's right gosh darn it. Even with the strong Can$ vs the slightly weaker U.S $.
                                It doesn't make sense.Looks like it's time for me to drive south of the boarder for a littls shopping spree while the iron is still hot! :-D

                              2. re: petek

                                I'm pretty open right now. The Carbonext was on my list of possibilities. Probably 270 or 300 mm.

                                I was actually gonna use it not specifically as a slicer, but try using it as a chefs knife for a while and see how i like that, since I like the slim narrow profile and straight edge of my Sakai Yusuke gyuto.

                                1. re: cowboyardee

                                  I really like some of the stuff Jon carries at JKI,spendy but sweet.

                            2. re: petek

                              :) To be honest, my next potential purchases are another Nakiri or another Usuba.... maybe a yanagiba one day.

                              Why? Well, I have a disfunctional usuba, so getting a few one is not a bad idea. I have a rather thick Tanaka Nakiri, so it will be nice to get a thin blade Nakiri and see what it can do.

                              1. re: Chemicalkinetics

                                What exactly is wrong with your usuba anyway? Is it fixable?

                                1. re: cowboyardee

                                  My fault. I was new to sharpening at the time and I grind the bevel in a wavy pattern (uneven grinding across the edge). Yes, it is fixable, but it will probably take hours. I tried to fix it a few times before, but the edge just chips like heck as I grind away. Maybe the DMT XXC stone really chips the edge.

                                  1. re: Chemicalkinetics

                                    Why don't you send it to someone(like Dave Martell) to get it fixed.Or do you ave your heart set on a new one?

                                    1. re: petek


                                      I suppose I could have Martell to take over the knife, but it is an inexpensive usuba to begin with. It is't the typical $250-$350 ones, let alone the more expensive one. I bought my Tojiro Shirogami usuba for maybe $80. Dave will probably charge more than the value of the knife to fix it. $25-45 for fixing the edge and another $50 for sharpening the knife:


                                      I can probably fix it but the blade is narrower/shorter than what I want already. I know the more I fix, the narrower it will get. I have a small/medium hand and even with that my knuckes can get very close to hitting the cutting board when I use it. I probably will give it another shot to fix it, just to see if I can do it, but really it is not worth from a fiscal point of view.

                                      1. re: Chemicalkinetics

                                        I see what you mean.Well then time to treat yourself to a nice new one :D

                                        1. re: petek

                                          Well, it is a cycle though. I really want to get an usuba to get good at katsuramuki, but the real honest question is: Do I really need a perfectly good usuba to learn katsuramuki? The answer is no. Just like I don't need a perfectly good bicycle to learn to ride a bicycle.

                                          I think a thin blade Nakiri is probably more practical for me. I am considering a Moritaka Aogami Super series one.


                                          Of course, I can always get another Chinese Chef knife as come to think of it.... so many many many choices. Now, of course, before all these knives, I am really considering getting a natural finishing waterstone. Problem is: I don't know anything about natural stone. There is absolutely no clear indication numbers like 8000 grits vs 10,000 grits. There are just a bunch of relative numbers like 5, 4, 3...etc.

                                          1. re: Chemicalkinetics

                                            That's like me. I'm considering a single bevel deba as my next purchase.Do I really need one? I don't clean a lot of whole fish at work,I'd have to learn how to use and sharpen a single bevel blade as well,the short answer is no the long answer is why not.I'm up for a new challenge,learning to use and sharpen a single bevel + I love the look,fell and weight of a deba.Now all I have to do is decide what steel I want and what make,model and size will suit me...

                                            Aren't you worried about the overgrind issue with the Moritaka?

                                            Natural stones are something I have no idea about,but one day would love to try one.Some of the ones I've seem cost hundreds,even thousands of $$.

                                            There's some info on the various knife forums.

                                            Speaking of katsuramuki,there's a really cool video of Chef Nobu using a yanagiba(I think) to do it.Amazing stuff. YouTube Martha Stewart and Nobu if you want to check it out

                                            1. re: petek

                                              "Aren't you worried about the overgrind issue with the Moritaka?"

                                              I am, which was why I got the Tanaka Nakiri. Originally, I wanted to get the Moritaka Nakiri. The Tanaka also had limited overgrinding issue, but a Tanaka knife is one-third to one-fourth the price of a Moritaka knife. The way rumor goes is that the overgrind issue is mostly for the lower end of the Moritaka knives and that the Aogami Super series is fine. Who knows...

                                              I saw some interesting video on katsuramuki and I have a book about it too. I had some limited successes in doing it with my Tojiro usuba. At the end of the day, it still comes down to practice and practice and I just have not practiced much.

                                    2. re: Chemicalkinetics

                                      If you get tired (or frustrated) of working on it, send it to me & I'll take a whack at it for you, no charge. I could use the experience for the sharpening side of my knifemaking venture.

                                      1. re: Eiron

                                        Thanks. I am a bit slow. I will try to send you the knife in coming next weekend. My email address is now visible in my profile, so send me your PO Box or your maiing address. I will keep my email address up for a few hours.

                2. *Rotating CarboNext Santoku*

                  I figure I will just expand this post instead of making a new post.

                  Eiron has offered to adopt my usuba knife, and we decide that it will be a good idea that he and his son to play with my CarboNext Santoku for a few days to evaluate the strength and weakness of the knife. Eiron is knowledge about knives in many aspects, but he pays especially close attention to handle design something I cannot compare to, so his and his son reviews will be valuable.

                  Although the CarboNext is not a very expensive knife (~$100), its steel is relatively undefined and mystical. I think we can rotate this knife among us. Feel free to use it how you like and feel free to sharpen it to see how it takes on a new edge and holds onto it...etc. I think that will be important for evaluation for an unknown steel. Just do not do any major reprofiling, but I guess that goes without saying. I know you guys and am very confident with your sharpening skill, so I have zero concern. The current bevel angle should be ~15°.

                  The upside of this offer is that you get to play with a knife for a few days to make up your mind about the knife. Maybe you are considering purchasing a CarboNext knife and want to test for this mystical steel just to be sure. Maybe you want to play with a Santoku just for the heck of it. The downside is that you are expected to pay for shipping to the next person in line. Don't worry about losing the knife in mail. If it is lost, it is lost. No one has to pay for a lost knife.

                  If no one is interested, then Eiron will send back the knife to me after he is done with it. Let Eiron and I know if you are interested, and he and I will come up a rotation list. You can respond to this post if you are interested and we will work on the contact information later (no need to post your address here).

                  18 Replies
                  1. re: Chemicalkinetics

                    Passaround!! Woot!.Too bad I live in Canada or I'd take you up on that offer.

                    1. re: petek

                      I was thinking about that. I don't worry so much about the shipping fee as the "custom". Do you know if the Canadian government charge for custom between US and Canada? I don't think so, but I am not sure.

                      P.S.: I take it back... it may be expensive to send to Canada.

                      1. re: Chemicalkinetics

                        Not only will it be expensive and most likely a hassle,but Canada Post is on strike(Or locked out) so no mail delivery up here. :(

                        1. re: petek

                          "but Canada Post is on strike(Or locked out) so no mail delivery up here"

                          Actually, I don't know if it will be expensive... aren't we in the NAFTA zone and should be free of many restriction. I didn't know the Canada Post is on strike. This is rather unusual.

                          1. re: Chemicalkinetics

                            "I didn't know the Canada Post is on strike. This is rather unusual."

                            Not up here it aint'

                            1. re: petek

                              This is not the first time? Are you saying this happen rather often?

                              1. re: Chemicalkinetics

                                It sure is a common occurance, but you could send it FedEx, UPS,Purolator(which is owned by canada post)

                                1. re: Dave5440

                                  I was just checking the JCK website and saw that even JCK mentioned about the Canadian strike. There it wrote:

                                  "Notice to Canadian Customers:

                                  Due to the recent strike by Canadian Post, Japan Post is temporary suspending acceptance of international postal items to Canada until the strike is over and the workers are back. We regret we are unable to make shipments to Canada at this moment.

                                  We apologize for this inconvenience and situation. Thank you for your attention."

                    2. re: Chemicalkinetics

                      I'd be interested, if we could make this work. Very generous of you, Chem.

                      1. re: cowboyardee

                        My pleasure, cowboy. When Eiron and I were thinking about the knife rotation, Petek and you were the first in my mind because I believe you two were/are considering buying a CarboNext knife. The knife should be on its way to Eiron's house and he will send it to you after he is finished (it seems Petek will be unavailable for testing). Eiron's email address is listed in his profile. You can email him your P.O. Box or mailing address. Take as much times as you need for testing. I have plenty other knives to use for the time being.

                          1. re: petek

                            :) We have not given up the idea yet. I am very bad at looking up shipping cost. I really don't think it should cost a lot to send a knife up to you in Canada. For cry out loud, JCK was able to send me a knife from Japan to USA in 3 days for a very reasonable price. The real thing I worry about is the custom. Technically, we are not selling you the knife (not buy/sell relationship), so there is no reason why the Canada government should put a custom fee on it, but we better make sure. I am sure the Canadian postal strike will end soon -- before cowboyardee finishes evaluating this knife.

                            1. re: Chemicalkinetics

                              I appreciate you considering me Chem, but I don't trust Canada Customs or Canada Post with your knife.One of the reasons I hardly order anything online.

                              1. re: petek

                                I just looked through some shipping options from UPS, USPS, and Fedex. Assuming I did the search correctly, UPS offers the best price. It will be $18 from where I live to Toronto. This is just an estimate as we won't be shipping from my address and you may not even live in Toronto. I assume the shipping fee from reverse direction (Canada to US) will be similar. Anyway, think about it. Don't worry about losing the knife as mentioned before. As for custom, I doubt the Canadian customs will really charge you for an inexpensive knife, especially we are not selling you the knife.

                                The only question you have to consider is that: Is it worth to pay ~$18 to test a knife for a week or two?

                                If you are interested, contact cowboyardee. If not, don't worry about it. Eiron and cowboyardee will tell you plenty about it.

                        1. re: cowboyardee


                          Eiron has received the CarboNext knife. If you are still interested, then email him your mailing address and he will send the knife to you after he is done. If not, don't worry about it. You can find his email address on his profile.

                            1. re: cowboyardee

                              Received, but nervous about replying due to the "warning".... :-D

                              1. re: Eiron

                                Heh, sorry bout that. I sent you another email from my work address, in case you need to reach me without buggy-ness.

                      2. Here is a link to my review. I didn't realize how long it was until after I posted it. Heh- sorry bout that.