A question about edge bevel

[youmakemehole]

I've got something here for the knife sharpeners and edge junkies of this forum – While I was sharpening one of my knives the other day, I was reprofiling the edge and I noticed that after a while of grinding away back and forth on both sides, there was just a tiny strip of the old edge on just one side that seemed to take too much effort to grind off. Being eager to try out my new edge, I said screw it and finished it up by stropping it as is. It performed wonderfully and I didnt have any issues removing the burr at all, and it got me thinking, why don't we ever see people setting setting a double bevel on just one side of the blade?

It seems to me to have several advantages - it is easier to grind, since you don't have to worry about over sharpening your bevel away/maintaining an even grind when you get to the other side, it takes less effort, it achieves the main purpose of the double bevel which is to leave a thicker, more stable edge, and it is also easier for the amateur to achieve a very small, nearly microscopic double bevel since it just involves one side. It is asymmetrical, but so are chisel grinds/serrations, and in this case, it is only a tiny part of the edge that is asymmetrical so it is actually hardly noticable.

So long story short, I'm just wondering if there are any good reasons why someone would not want to grind a one sided "1.5" bevel so to speak, and if it is a viable option when sharpening knives? If I didn't make myself clear, what I mean is an edge that is single beveled on one side, and double beveled on the other. This would be achieved by forming an even grind on both sides at a lower degree angle without needing to form a burr necessarily and then using a larger angle to only grind a secondary bevel on only one side of the edge until a proper edge/burr is formed.

[Enactive]

You mean a chisel ground microbevel?

[youmakemehole]

Is that what it is? I had never heard of such a thing

[Pelagic]

If your overall inclusive angle isn't too obtuse and you have proper apex formation, you'll see good performance. Symmetry isn't an absolute necessity. Chisel grinds have their place in food prep. Just do what works for you.

[Albatross]

To me, it sounds like you're asking about a standard blade grind, that's simply sharpened on one side? Not just a chisel microbevel, but a chisel bevel. Is this correct?

Doesn't Enerson do this on some of their knives?

[Michael Janich]

Phill Hartsfield was a leading force in advocating chisel-ground edges. He influenced Ernie Emerson, who also incorporates them on many of his designs. One of the basic classes of Japanese kitchen knives (kataba, as opposed to ryoba) uses single-bevel edge geometry.

I had the honor of attending a presentation and cutting demonstration by Phill Hartsfield when I taught at Gunsite's Edged Weapon Symposium in 1998. Phill felt the single-bevel provided more acute edge geometry and better cutting performance. His custom knives argued that claim pretty effectively.

Stay safe,

Mike

[youmakemehole]

To me, it sounds like you're asking about a standard blade grind, that's simply sharpened on one side? Not just a chisel microbevel, but a chisel bevel. Is this correct?

Doesn't Enerson do this on some of their knives?

No, not a chisel grind, a chisel grind would have one side flat and the other side ground, what I'm talking about is a microbevel that only exists on one side, both sides of the blade are ground though. Most of my knives I sharpen to a single bevel on both sides, I know the cutting performance is going to be superior compared to the same angle with a more obtuse microbevel added on, but from what I understand, a microbevel allows an even more acute primary bevel by introducing a more obtuse angle via a secondary microbevel at the very edge of the blade which stabilizes an otherwise fragile edge that would not be robust enough to handle the primary bevel (ground to a very low angle). What I am thinking, is that this microbevel can perhaps only be needed to be introduced on one side, it serves a similar purpose, but allows knife owners who arent necessarily professional knife sharpeners to grind a very minuscule secondary bevel that would be tough to do if it was two-sided. I know what I'm trying to get across here is probably still confusing to some so I'll try to see if I can capture what I did earlier in some photos and put them up when I have the chance.


Edit: first image shows one side with a microbevel, second one has the other side of the blade with only the primary bevel. hard to see, i know, it was the best I could do after multiple attempts though.

[youmakemehole]

Phill Hartsfield was a leading force in advocating chisel-ground edges. He influenced Ernie Emerson, who also incorporates them on many of his designs. One of the basic classes of Japanese kitchen knives (kataba, as opposed to ryoba) uses single-bevel edge geometry.

I had the honor of attending a presentation and cutting demonstration by Phill Hartsfield when I taught at Gunsite's Edged Weapon Symposium in 1998. Phill felt the single-bevel provided more acute edge geometry and better cutting performance. His custom knives argued that claim pretty effectively.

Stay safe,

Mike

Very interesting background there Mike, thanks for that info. I know that professional sashimi chefs exclusively use chisel ground knives to slice their raw fish as it creates a cleaner and more uniform cut that also is aesthetically pleasing compared to a traditionally ground chef's knife. Chisel grinds are also so simple to sharpen regardless of what sort of knife or application and I'd imagine it to be the easiest type of edge to get super sharp for a beginning knife sharpener. Now if one is to apply that reasoning to the secondary bevel, aka the microbevel, after both sides of the knife have been sharpened to their primary angle, that would be what I'm trying to get at in my first post. This microbevel is often taken out by the knife owner after the first sharpening, probably because it is easier to just grind each side once with one angle, and also because a single bevel can provide higher performance, but thats not to say that a microbevel provides benefits as well, and I think being able to get those benefits without the precision needed to get it perfect on both sides of the blade might encourage sharpeners to perhaps utilize such a feature more often?

[Evil D]

I think the biggest risk is if you keep sharpening this way the edge would eventually become off center of the blade. Not exactly the end of the world but something that would drive me crazy. That wee little bit of old bevel is always the hardest part to get rid of when reprofiling because the closer it gets to being removed the more metal you have to grind to get it there. I once reground a ZDP Delica down to 10 degrees per side on a Lansky...chalk that up as something I'll never ever do again.

[youmakemehole]

That makes sense, that would be good to watch out for I agree. And I thihnk you hit the nail right on the head... I had reprofiled one side to 12 degrees and completely removed the old bevel, thinking I must have ground it to at least the center of teh blade by doing so, I started working on the other side, and lo and behold, the new grind bevel started to look even taller than the other side, but with some of the old bevel still remaining! I am still unsure of how this happened, or perhaps it was incorrect of me to think that removing the old bevel = grinding pas the center? My mind is still a bit boggled. Thanks goodness this was not ZDP, I've reprofiled ZDP to around 12 degrees before too and was very lucky nothing went wrong that time. ZDP definitely is one of those steels that doesnt forgive at all if you prematurely switch to a finer grit.

[Albatross]

To me, it sounds like you're asking about a standard blade grind, that's simply sharpened on one side? Not just a chisel microbevel, but a chisel bevel. Is this correct?

Doesn't Enerson do this on some of their knives?

No, not a chisel grind, a chisel grind would have one side flat and the other side ground, what I'm talking about is a microbevel that only exists on one side, both sides of the blade are ground though. Most of my knives I sharpen to a single bevel on both sides, I know the cutting performance is going to be superior compared to the same angle with a more obtuse microbevel added on, but from what I understand, a microbevel allows an even more acute primary bevel by introducing a more obtuse angle via a secondary microbevel at the very edge of the blade which stabilizes an otherwise fragile edge that would not be robust enough to handle the primary bevel (ground to a very low angle). What I am thinking, is that this microbevel can perhaps only be needed to be introduced on one side, it serves a similar purpose, but allows knife owners who arent necessarily professional knife sharpeners to grind a very minuscule secondary bevel that would be tough to do if it was two-sided. I know what I'm trying to get across here is probably still confusing to some so I'll try to see if I can capture what I did earlier in some photos and put them up when I have the chance.


Edit: first image shows one side with a microbevel, second one has the other side of the blade with only the primary bevel. hard to see, i know, it was the best I could do after multiple attempts though.

Ah, I see now. Misread it. Although, it seems like a chisel bevel would work better, since the chisel microbevel, would eventually lead to the same edge geometry anyway, unless re-profiling was done on a semi-regular basis, which takes away from the convenience it originally offered. Maybe it's not important though.

[youmakemehole]

Perhaps something could happen where alternating sides became the microbevel after sharpenings? This would require a very small microbevel in order not to remove too much material each time, but could solve the issue of becoming off center while making it easy for the sharpener, as only one side needs to be sharpened each time, and perhaps with 1/2 the effort as well. I've sure put a surprising amount of thought into this by now, for me as a fairly amatuer sharpener though, it just might prove to be something useful I can further experiment on in the near future.

[Mattysc42]

I use diamond lapping films pasted to balsa to sharpen my knives once I reach that last part when reprofiling. This helps to ensure the apex gets hit quickly by slightly convexing the bevel. With repeated sharpenings the bevel becomes a smooth curve into the apex, though the edge is hair splitting long before that. I reprofiled my maxamet manix to a 13.5dps convex from 17.5dps in about half an hour on my wicked edge last week by using this method.

[vivi]

Microbevels by their nature must be very small to be a microbevel. Some of the "microbevels" I've seen images of are really just normal bevels with the shoulder ground down a bit.

I've thought about your idea and personally I'm not convinced it would make sharpening significantly easier. Sharpening is already made much easier with a microbevel because it takes so few strokes. If you only sharpen one side you're still going to do burr removal on the back side.

Maybe I can try it on a knife and see how it goes.

[youmakemehole]

Right, but burr removal on something so minute can be done during stropping, which is a step that is necessary for most knives anyways. I don't know if I am trying to say that it would make sharpening significantly easier, but it may just be helpful for someone who is trying to get used to microbeveling by serving as a less intimidating process of achieving it.

[Bloke]

While I was sharpening one of my knives the other day, I was reprofiling the edge and I noticed that after a while of grinding away back and forth on both sides, there was just a tiny strip of the old edge on just one side that seemed to take too much effort to grind off. Being eager to try out my new edge, I said screw it and finished it up by stropping it as is.

I'm happy with about 90% of the edge cleaning up when I initially set a bevel and can't see the point or value in grinding good blade steel away to get to a section of the blade that has an obtuse over grind in one small section. I just keep the bevel even on both sides use the knife as per normal and eventually after a few full sharpenings that small section of over grind cleans up. :)

[vivi]

Right, but burr removal on something so minute can be done during stropping, which is a step that is necessary for most knives anyways. I don't know if I am trying to say that it would make sharpening significantly easier, but it may just be helpful for someone who is trying to get used to microbeveling by serving as a less intimidating process of achieving it.

I don't think stropping is ever necessary, but if this method helps someone learn to sharpen better, then whatever works. Everyone is different.

While I was sharpening one of my knives the other day, I was reprofiling the edge and I noticed that after a while of grinding away back and forth on both sides, there was just a tiny strip of the old edge on just one side that seemed to take too much effort to grind off. Being eager to try out my new edge, I said screw it and finished it up by stropping it as is.

I'm happy with about 90% of the edge cleaning up when I initially set a bevel and can't see the point or value in grinding good blade steel away to get to a section of the blade that has an obtuse over grind in one small section. I just keep the bevel even on both sides use the knife as per normal and eventually after a few full sharpenings that small section of over grind cleans up. :)

I agree.

When I reprofile knives, I often intentionally leave a microbevels worth of factory edge. This lets me ensure that I don't waste any blade when I reprofile the edge, and I sharpen my microbevels near factory angles anyways. It also means there's no bur to clean up.

[Deadboxhero]

Adding a microbevel makes the edge less sharp and thicker. It trades performance for durability and convenience.

[Bloke]

I'm happy with about 90% of the edge cleaning up when I initially set a bevel and can't see the point or value in grinding good blade steel away to get to a section of the blade that has an obtuse over grind in one small section. I just keep the bevel even on both sides use the knife as per normal and eventually after a few full sharpenings that small section of over grind cleans up. :)

I agree.

When I reprofile knives, I often intentionally leave a microbevels worth of factory edge. This lets me ensure that I don't waste any blade when I reprofile the edge, and I sharpen my microbevels near factory angles anyways. It also means there's no bur to clean up.

I feel it's the logical way to go and the only thing I can add is, I treat any chips I may incur the same way. :)

Adding a microbevel makes the edge less sharp and thicker. It trades performance for durability and convenience.

I’m inclined to agree Shawn and if I free handed I most likely wouldn’t use a micro bevel though I’m not too sure a micro bevel does impact sharpness. :confused:

[Deadboxhero]

I'm happy with about 90% of the edge cleaning up when I initially set a bevel and can't see the point or value in grinding good blade steel away to get to a section of the blade that has an obtuse over grind in one small section. I just keep the bevel even on both sides use the knife as per normal and eventually after a few full sharpenings that small section of over grind cleans up. :)

I agree.

When I reprofile knives, I often intentionally leave a microbevels worth of factory edge. This lets me ensure that I don't waste any blade when I reprofile the edge, and I sharpen my microbevels near factory angles anyways. It also means there's no bur to clean up.

I feel it's the logical way to go and the only thing I can add is, I treat any chips I may incur the same way. :)

Adding a microbevel makes the edge less sharp and thicker. It trades performance for durability and convenience.

I’m inclined to agree Shawn and if I free handed I most likely wouldn’t use a micro bevel though I’m not too sure a micro bevel does impact sharpness. :confused:

So if you have an edge at 10dps but add a 12dps microbevel you have taken away the advantage of the 10dps for what the apex makes contact with, it's now a 12dps edge.

I say just do what ever works for you.

I don't think we'll all need to have a cenus on every little detail here. Plenty of ways to do stuff. I have the most success with no micro.