Lets say I sharpend my knife starting with Grit 400, then 1000 up to 3000 and 6000 but its still is too dull.

If i want to sharpen the blade again do I restart with grit 400 or 1000 ? And is there a way to tell where to start again?

  • 7
    If you sharpened it all the way up to 6000 grit, and it's still too dull, you either did something wrong, or you're a elite ninja assassin. Commented Jan 14, 2020 at 7:53
  • When you say "too dull", does it pass the paper test? If it does pass, it's sharp enough for almsot anything I can think of. If it doesn't, you probably did something wrong...
    – John Doe
    Commented Jan 15, 2020 at 10:27

2 Answers 2


Grit means very little for sharpness beyond ~2000. Far more important is a consistent angle.

This is a good article that explains the angles

a good sharpening tool will have a angle guide, something like this

I'd recommend against "eyeballing" it the first few times.

Joerg Sprave made a nice video explaining a lot, he uses the Gatco set I linked.

And don't forget to hone your knife before trying the edge! In my experience that is the bit that pushes a edge from "eh, not bad" to "whoooo/


  • 600 grit diamond is my limit. As you say, angle is of utmost importance. Commented Jan 15, 2020 at 2:07
  • @Borgh Is using Grit 400 the same as to hone?
    – Herrsocke
    Commented Jan 15, 2020 at 3:46
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    @Herrsocke honing is a whole different process. Sharpening actually removes metal, honing using a honing steel (en.wikipedia.org/wiki/Honing_steel) just straightens out the edge.
    – Borgh
    Commented Jan 15, 2020 at 9:09
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    @WayfaringStranger I have a dual sided sharpening block, grit 400 and 1000. Thats plenty for my home cooking.
    – Borgh
    Commented Jan 15, 2020 at 9:10
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    @Borgh I've a 4 sided diamond block for lathe bit sharpening. Works great for kitchen knives too. I just go with what works. 600 is nice, 1000 will probably work just as well. You simply need a course and a fine. Commented Jan 15, 2020 at 12:27

There is no set way of knowing exactly what grit to use but you can estimate. <1000 grit is for repair, so I would suggest visual inspecting the blades edge under a light. If there are any points that reflect light differently, or that you can see any damage, then use the 400 grit until the edge is consistent. If your knife passes the visual check, but struggles to cut consistently along the length of the blade (newspaper will be a good test of this consistency), then i would start at 1000. If your blade is already sharp enough to shave hairs but you want it to split atoms, start at 3000 but you may need to look beyond stones to leather strops and polishing compounds.

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