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Jun 29, 2014 12:38 PM

Grinding scratches on a new damascus pattern knife?

Just bought a good japanese knife. Upon further inspection I noticed there are lots of grinding marks on one face of the knife that shows up when tilted at a bright light.

Anyone knows if this is normal for a quality knife?

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  1. If it is a brand new knife, then no, this is not normal

    1) It isn't a brand new factory knife.
    2) It is a so called "second". Products sold with cosmetic flaws
    3) It is made by a custom knife maker by hands

    That being said, the grind mark (or lack of it) is not indicative of the quality of a knife.

    1 Reply
    1. re: Chemicalkinetics

      Supposed to be brand new. And yes it's hand made but probably assisted by machines. The store offered a replacement however it is highly unlikely for me since im overseas and it's difficult to ship back knives in the US. The brand is actually kasumi.

    2. If you are looking at a one of the semi-ubiquitous VG-10 clad "faux damascus" knives, then that is a pretty common characteristic on many of the knives I have seen. The effect I see is faint.

      Are the grind marks very noticeable? Are they a bunch of parallel striations, or are they lines in a bunch of random directions?

      20 Replies
      1. re: Cynic2701

        Interesting. I haven't notice the couple I have handled. Maybe I wasn't looking closely enough.

        1. re: Chemicalkinetics

          Try tilting it under a bright pin light bulb and try to see if its there. It took me a while to before I noticed.,

        2. re: Cynic2701

          There are certainly random marks but it's faint and doesnt bother me. (scratches for sure)

          I also noticed some brushed strokes probably the polishing strokes since it's to uniform but again only shows up on light.

          The one's Im concerned with are grind marks on one side it's a bit too much. It's not deep that I can feel the grooves but is shows up under bright light. It's suppose to be handmade but I really don't know if it's suppose to be there with their skill. (japanese makers)

          1. re: juandelecruz123

            Grind patterns are grind patterns. You will have grind marks unless the blade is polished to a mirror finish--which isn't really desirable for a kitchen knife, as you will gets lots of stiction.

            This isn't a kitchen knife, but it is a VG-10 blade. It's hard to tell, but there is sort of a mottled sheen/grind striations to it. Is this the effect that you see?

            (These pics aren't mine)



            1. re: Cynic2701

              I just took some pics, it's really difficult to capture with a camera so I turned the flash on just to get highlight the marks.
              The one on the tip looks like grind marks.
              The rest are kinda polishing marks it's all over the body of the blade but only a few shows up on this shot(as ive said it shows up at an angle with a bright light.

              It actually took me quite a while to notice those marks. I actually love the way the knife cuts and feels. Just a shame if those marks shouldn't be there.

              1. re: juandelecruz123

                Ok, those marks are definitely not intentional nor do they appear to be part of the manufacturing process. They look like they occurred after production--perhaps the knife was sitting in a stack with other knives and clattered around.

                The outer cladding on these type of knives is typically a softer, though highly corrosion resistant, steel in comparison to the core steel. If I recall correctly, Shun uses SUS-410 and others use 410 J2 and 420 J analogs. These steels are easily scratched--to the point that cutting paper can leave marks due to left over silicates in the paper's mix.

                In any case, I doubt that that is a manufacturing defect, and more likely something that happened during storage, transportation, or boxing of the knife.

                1. re: juandelecruz123

                  Even further, the picture of the marks near the tip makes it look like someone tried to sharpen it at too low of an angle.

                  1. re: juandelecruz123

                    I’ve never seen scratches like that on a new knife, but as Cynic said the cladding on those VG-10 blades are very soft, and easily scratched. Plus, scratches are more easily seen with shinier vs. matte finishes.

                    Yours appear to have been marred by some sort of horizontal slotted knife drawer. If the Kasumi cladding is the same as Shuns’ cladding (which I believe it is), expect a lot more scratches from normal usage and washing. Avoid anything abrasive including hard sponges.

                    1. re: JavaBean

                      The horizontal looks like as you've said from storage. But the vertical curved lines looked much more like stokes than scratches. Thanks for the info.

                      1. re: juandelecruz123

                        I've sharpened a few shun classic with a boatload of surface scratches. Aside from looking like crap, the scratches didn't effect on the knifes' performance. I got most of the scratches out with wet fine (1k, 2k grit) wet/dry sandpaper and metal polish. But, left the deep and super fine, spiderweb scratches alone b/c I didn't want to mess with the Damascus pattern.

                        1. re: JavaBean

                          Wouldn't sanding the scratches out ruin the pattern?

                          1. re: juandelecruz123

                            In general the more you sand or polish a damascus, the more subdued / blurred the pattern, the lines or veins become less dark.

                            The viens on the Shun aren't very dark to begin with, so i was able to polish out some of the scratches without making the veins less dark.

                            1. re: JavaBean

                              Have you heard of anyone doing an acid etch on the stainless faux-damascus that Shun uses? Would that be helpful at all?

                              1. re: Cynic2701

                                Yes, I recall Dave Martel @JapaneseKnifeSharpening, and one or two other hobbyists were able to re-etch a shun. Iirc, they used a diluted solution of etching fluid, dipped the blade for a few seconds at a time, redipped as needed.

                                I was going to try it myself with muriatic acid ( couldn't find etching solution), but I didn't want to experiment on a knife that wasn't mine.

                                1. re: JavaBean

                                  Interesting, I wasn't sure it would work or not, thanks!

                    2. re: juandelecruz123

                      Oh I see. These are very shallow scratches, right? I agree with JaveBean. Even if the knife was perfect out of box, it will likely acquire scratches over time.

                      The knife is perfectly fine. These look to be a cosmetic scratches. I see no indication of poor manufacturing problem here.

                      1. re: Chemicalkinetics

                        Yes, couldnt even feel it. Contacted manufacturer and they said scratches could be from the grinding. Maybe in this case there was a bit of carelesness. Was just concerned that this was a second factory knife but these the handles look perfect only the blades got some of this annoying scratches. Thanks

                        1. re: juandelecruz123

                          Yeah, I know the seller told you that you can ship back, but you said this is not a realistic option for you, right? It is annoying, but in my opinion, the knife should be perfectly fine beside the scratch mark. I won't think it is a sign of poor workmanship. In other words, I don't think there is a "deeper" problem.