Centering an edge

[Bindlestiff]

How important is centering the edge?

I use an Edge Pro for establishing the primary edge and a
Sharpmaker for maintenance - nothing revolutionary here.

After a session with the Edge pro, I typically follow up with a few
(maybe 5) passes on a Sharpmaker ( fine stones, on the flat) to set the
secondary bevel.

I have noticed that if I follow the traditional advice and
grind on the Edge Pro until I get a burr, then reverse the side
until I get another burr, I get a primary bevel that is
considerably wider on one side, suggesting that the factory
grind was not centered.

I have had this experience with several Spyderco knives, known
for the excellence of their factory edges. I have also had this
problem with Benchmade knives, not especially known for their
factory edges although with some work, I was able to obtain a
good edge eventually.

Question: How important is centering the edge or am I doing
something wrong?

 

[tim8557]

I don't know if it's important or not. I would suggest that you call Edge Pro and ask. There's a good chance that Ben Dale will be there and take your call. One of the nicest people you'll ever talk to and an absolute "Student of the Art of Sharpening".

 

[Joe Talmadge]

Question: How important is centering the edge or am I doing
something wrong?

I like to keep the edge at least vaguely centered, just because it appeals to my sense of balance. Instead of grinding one side only until you get a burr -- which can definitely lead to an uncentered edge -- just modify the procedure by going (say) 2 minutes on one side, and if no burr appears, two minutes on the other side. Repeat until one side starts burring, then follow the usual instructions: continue with that side only until you have a burr along the entire edge length. This keeps the edge centered.

 

[Laceration]

I've found quite a few of my knives don't have a truly centered edge. It becomes most obvious when you change the edge profile. I don't think there's anything you can do about it except use a different angle for each side so the grind looks even. For example, I was thinning the edge of my M16 and it seems that one side is ground at 20 degrees while the other is 25 degrees. I am bringing it down to 17 degrees on one side and 20 degrees on the other. I'm going to see how that works for awhile and then I might just sharpen both sides at 17 degrees. It takes forever with the Lansky though.

 

[db]

Don’t blame the factory grind it may not be off. In some cases it is but this is a problem with the burr method of sharpening. If you grind away on one side only until the burr forms you will also be moving the edge off center in most cases. The fix is like Joe said, if you grind, let’s say 40 strokes and no burr forms, flip to the other side and do 40. The fix is to not grind too much on one side without doing the other side. This will keep your edge in the middle. It’s not really a problem if your edge isn’t centered however I do like them in the middle. I’m right handed and if I do move the edge to one side I like it over to the left, looking at it from the spine up. Some Kitchen knives are done this way on purpose.

 

[Laceration]

I usually use an equal amount of strokes on each side and still it's off center. Not all of my knives are like that and I've found that it doesn't really affect the performance. It just looks funny, especially on coated blades.

 

[Joe Talmadge]

I usually use an equal amount of strokes on each side and still it's off center. Not all of my knives are like that and I've found that it doesn't really affect the performance. It just looks funny, especially on coated blades.

Ya, slightly off doesn't affect performance at all. In your case, if you do an equal amount on each side and it's off, then spend more time on the side with the smaller bevel until they even out. I find it usually only takes a few sharpenings to center even a really off-center edge.

 

[fulloflead]

I like to keep the edge at least vaguely centered, just because it appeals to my sense of balance. Instead of grinding one side only until you get a burr -- which can definitely lead to an uncentered edge -- just modify the procedure by going (say) 2 minutes on one side, and if no burr appears, two minutes on the other side. Repeat until one side starts burring, then follow the usual instructions: continue with that side only until you have a burr along the entire edge length. This keeps the edge centered.

This is what I do when I reprofile... now. But I have a bunch of off-center edges on knives from when I used to reprofile one side at a time. It doesn't really bother me and I've never seen it make one bit of difference.

Another thing you can do is, the next time you sharpen your knife, start from the other side.

.