Burr and getting rid of it?

T

tommytman

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Aug 12, 2019
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I can get a burr when sharpening. For example I can use a coarse diamond stone and get a burr on one side and then switch to the other side of the blade and push the burr to the opposite side.
Now I move to the fine stone. What is my strategy for getting the burr removed?
 
Light light pressure. The weight of the knife or stone. I usually remove the burr with coarse. Sometimes even raise another with the finer stone. But the key is light pressure to remove it without flipping it again.
 
Depends on the steel. Some are easy to de-burr from the stone, some are seemingly impossible.
 
With the burr all on one side, remove it with light, leading passes at twice the original angle.

Check every pass and stop when you cannot feel/detect it anymore. If you still have it in one area and not the other, only work the area where the burr remains. Follow up with a few light passes at the original angle and move on to the next stone.
 
Mr.Wizard said:
FYI (not for you HH) that can be really hard to do on a soft, gritty water stone.
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Yeah, on a softish stone you might not even have to elevate the spine - just use some leading passes to eliminate it and finish with a few light trailing passes.
 
if you get a blade you have lots of trouble getting the burr removed one thing I do occasionally is just lightly draw the blade over a pine 2×4 just like you were cutting something ... but only very lightly ... usually one or two light draw strokes will usually remove the burr.
 
For me it is easier to remove a burr on a coarse gritty stone than a fine, like a India. Perhaps because I work more on a coarse stone. DM
 
jpm2 said:
Depends on the steel. Some are easy to de-burr from the stone, some are seemingly impossible.
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Yeah good point, the first time I sharpened VG10 I had a burr from hell that took forever to remove. That's what I like about M390, 204P... very small burr to begin with and pretty easy to remove.
 
brando555 said:
Yeah good point, the first time I sharpened VG10 I had a burr from hell that took forever to remove. That's what I like about M390, 204P... very small burr to begin with and pretty easy to remove.
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The 2 specimens of VG10 are among the worst I have when it comes to burr removal, one of the reasons I have only 2.

I wonder if hardness of the steel has anything to do with it, because all the knife blades I have that are confirmed 62+ hrc don't give near as much trouble, and .... Spyderco maxamet which seems to be the hardest production knife steel in existence is the easiest of all.
 
jpm2 said:
The 2 specimens of VG10 are among the worst I have when it comes to burr removal, one of the reasons I have only 2.

I wonder if hardness of the steel has anything to do with it, because all the knife blades I have that are confirmed 62+ hrc don't give near as much trouble, and .... Spyderco maxamet which seems to be the hardest production knife steel in existence is the easiest of all.
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Yeah you're right, I believe it's the hardness and fine grain structure of the powdered "super steels", compared to something like VG10 or other ingot steels like D2 which can be tougher to sharpen. I wish I could elaborate but I'll leave that to the steel gurus!
 
This following is an oversimplification really as composition and metallurgy play a huge role, but generally the harder a material the more brittle and less ductile it is.

Ductility is a result of the grains in a material being able to slide across one another, a feature that is reduced with smaller grain sizes and particularly the existence of carbides which act to pin the grain boundary. When you are sharpening you are applying force to the edge which applies a bending moment at the same time as you are grinding metal - hence the formation of a burr. Effectively you induce ductile deformation at the same time.

In a hard metal this is less prevalent so a smaller burr is formed for the same level of applied force; as well as the burr being more brittle resulting in it more easily being sheared off.

You obviously wouldn’t want your knife to bend in half, but ductility is very important for things like copper wire.
 
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