Sharpening Strokes...

[cotedupy]

I'm unsure whether this question is blindingly obvious, somewhat niche, or completely irrelevant. But if I was a betting man I'd probably back all three to come home...

I can do an edge-leading stroke like this, going from the bottom right to the top left:

I can also do an edge leading stroke like this, going from the bottom left to the top right:

The first example is an edge and tip leading stroke, the second is an edge and heel leading stroke. And the same obviously applies to trailing strokes. So my question is: Do you think it makes a difference? What if you did one type on one side and one type on the other, would that matter?

(And as a follow-up bonus question for anybody still here... Why the feck do I occupy my time thinking about this nonsense?)

 

[captaincaed]

Because once you learn a little, you want to learn a whole lot more!

I've found a subtle effect yes. Tooth orientation affects my cuts on tough veggie skins. Push should cut easier because you increase the weight behind the edge as you go from initiating the cut to finishing the cut. However when I sharpen as you show in the second picture I get an easier cut pulling the knife from heel to tip through the pepper skin. I think this is because of the tooth orientation. I don’t seem to notice any real difference when cutting through tough skin is not a factor. And I think the effect is fairly subtle but I think it’s there. I Imagine if I were doing bulk prep I wouldn’t think about it that much.

Edited for poor grammar

 

[ModRQC]

Funny, the only time I breached the tooth or general scratch pattern orientation subject, people were like and looking down on the post with half amusement, half condescending replies.

Will be eager to see this thread evolve.

 

[Benuser]

I'm unsure whether this question is blindingly obvious, somewhat niche, or completely irrelevant. But if I was a betting man I'd probably back all three to come home...

I can do an edge-leading stroke like this, going from the bottom right to the top left:

View attachment 142699

I can also do an edge leading stroke like this, going from the bottom left to the top right:

View attachment 142698

The first example is an edge and tip leading stroke, the second is an edge and heel leading stroke. And the same obviously applies to trailing strokes. So my question is: Does it make a difference? What if you did one type on one side and one type on the other, would that matter?

(And as a follow-up bonus question for anybody still here... Why the feck do I occupy my time thinking about this nonsense?)

I want the scratch pattern to be close to orthogonal. But my basic problem with the first photo is with the handle. Not necessarily with this knife, but with this motion the handle or a bolster or virole may bump against the stone.

 

[cotedupy]

I want the scratch pattern to be close to orthogonal. But my basic problem with the first photo is with the handle. Not necessarily with this knife, but with this motion the handle or a bolster or virole may bump against the stone.

Haha... yes. The pictures was more just to explain the directions I meant. Obviously when actually sharpening it's not going to be like that all the way along!

 

[inferno]

use the most ergonomic/comfortable way imo!

 

[cotedupy]

Cheers guys! Sounds like people reckon it's too marginal a difference to really spend too much time thinking about.

Was just something I'd always wondered, because when I do edge leading de-burring or micorbevel strokes I do tip first on the left side of the knife, as in the first picture, and heel first on the right side, going from top left to bottom right. (I sharpen one-handed).

I'm not going to be changing my spots now, but was just wondering what people thought.

The thread hasn't been entirely pointless though, as Benuser has introduced me to a useful new word - 'orthogonal'!

 

[inferno]

i do heel to tip edge leading. both away and towards me. but i also angle my stone 45degrees to the right. away side of stone is more to the right.

 

[cotedupy]

i do heel to tip edge leading. both away and towards me. but i also angle my stone 45degrees to the right. away side of stone is more to the right.

For some reason it'd never even crossed my mind to change the angle of a stone. I might have a play around with that!

 

[inferno]

i feel it gets a lot more ergonomic this way.

 

[captaincaed]

Angling the stone is a pro move. Love it.

 

[ModRQC]

Angling the body to the stone; and most pros adopt stationary stances, although it might or might not be angled to the stones.

I still like angling the stone: sometimes makes up for either space deficit, shorter lengths blades, or blade to handle problematic configuration for regular strokes.

Orthogonal: essentially, "at right angles".

Or:

As adjectives the difference between perpendicular and orthogonal is that perpendicular is (geometry) at or forming a right angle (to) while orthogonal is (geometry) of two objects, at right angles; perpendicular to each other.

And to be sure...

...the cutting edge is perpendicular to the direction of tool travel.

@Benuser has always been advocating this to me.

I've done a bit of both: natural strokes vs. trying to make @Benuser technique's natural. Since I'm basic skills, I'll just say this: Ben is patient even in the minutia of being patient. But I remember also that following his directives, a noob could get nice results. With specific knives I still follow his praxis, whereas for more utilitarian knives I go all natural strokes. Admittedly, the latter are gaining ground in sharpness. Still... taking some additional time to make things perfect usually yields slightly better results. And that's where I stop... but I believe Ben is rather the kind of guy that will deeply have studied minutia differences of "slightly best" result until he could reproduce "best" consistently.

 

[cotedupy]

Angling the body to the stone; and most pros adopt stationary stances, although it might or might not be angled to the stones.

I still like angling the stone: sometimes makes up for either space deficit, shorter lengths blades, or blade to handle problematic configuration for regular strokes.

Orthogonal: essentially, "at right angles".

Or:

As adjectives the difference between perpendicular and orthogonal is that perpendicular is (geometry) at or forming a right angle (to) while orthogonal is (geometry) of two objects, at right angles; perpendicular to each other.

And to be sure...

...the cutting edge is perpendicular to the direction of tool travel.

@Benuser has always been advocating this to me.

I've done a bit of both: natural strokes vs. trying to make @Benuser technique's natural. Since I'm basic skills, I'll just say this: Ben is patient even in the minutia of being patient. But I remember also that following his directives, a noob could get nice results. With specific knives I still follow his praxis, whereas for more utilitarian knives I go all natural strokes. Admittedly, the latter are gaining ground in sharpness. Still... taking some additional time to make things perfect usually yields slightly better results. And that's where I stop... but I believe Ben is rather the kind of guy that will deeply have studied minutia differences of "slightly best" result until he could reproduce "best" consistently.

This is interesting. My angle is certainly flatter than the pictures above, but it kind of mimics the shape of the knife. On a nakiri / usuba / very flat profile it would be perpendicular, for knives with more belly, or at the tip, it changes.

But that's just what feels natural for me, and seems to work. I also use more single, full-length passes than I imagine a lot of people do.

 

[kayman67]

i do heel to tip edge leading. both away and towards me. but i also angle my stone 45degrees to the right. away side of stone is more to the right.

Heh, I do this as well. Might just be a natural change.

 

[ian]

However when I sharpen as you show in the second picture I get an easier cut pulling the knife from heel to tip through the pepper skin. I think this is because of the tooth orientation.

Funny, the only time I breached the tooth or general scratch pattern orientation subject, people were like and looking down on the post with half amusement, half condescending replies.

Idk if one of my responses before seemed condescending. It’s a reasonable hypothesis, it’s just that I’ve never seen any blown up image of a knife edge where there was any orientation to the teeth, so I’m inclined to think it doesn’t work like that, and that the way teeth are formed is more like breaking than cutting out uniform grooves. The surface finish on the bevel can be oriented, but idk if that makes a difference.

@captaincaed, I suspect that the reason pull cuts are easier for you (and most people) on pepper skins is not because of tooth orientation, but rather because body mechanics make it easier to put more horizontal action in a pull cut than in a push cut. So more sawing, less straight down chop.

 

[Delat]

I also do edge-leading by starting with the heel. I think what we’re doing unconsciously is starting with the handle of the knife at the closest approach to the stone so we can naturally use the full length of the stone. If you start with the tip and misjudge your stroke, then the handle bangs into the stone before you’re ready.

Since we’re talking about minutiae, one thing that goes through my mind when I’m doing this is how much time each portion of the blade spends on the stone. It feels like the heel travels a shorter distance across the stone due to the starting position (dictated by the handle), whereas the tip travels almost the full length of the stone unless you purposely stop a bit early to compensate.

 

[kayman67]

I push the heel a bit more first. I think this would develop into a natural motion as well after doing some edge checks.

 

[Luftmensch]

Do you think it makes a difference?

Probably depends on how you cut and what grit you finish!

There is old wisdom that the teeth (scratch pattern) should point towards the cut direction - like a saw. For foundation work i just use any orientation that feels right at the time. Since I prefer pull cuts more than push cuts, I orient my scratch pattern towards the heel on finishing strokes. I have done this blindly and never really bothered to test whether it matters. I suspect it may have a small to negligible effect for low grit 'toothy' edges. I doubt it does anything at higher grits.

Why the feck do I occupy my time thinking about this nonsense?

Did you check? Maybe you had a (sharpening) stroke ....

 

[ian]

Did you check? Maybe you had a (sharpening) stroke ....

Boo!

 

[inferno]

Probably depends on how you cut and what grit you finish!

There is old wisdom that the teeth (scratch pattern) should point towards the cut direction - like a saw. For foundation work i just use any orientation that feels right at the time. Since I prefer pull cuts more than push cuts, I orient my scratch pattern towards the heel on finishing strokes. I have done this blindly and never really bothered to test whether it matters. I suspect it may have a small to negligible effect for low grit 'toothy' edges. I doubt it does anything at higher grits.






Did you check? Maybe you had a (sharpening) stroke ....

sometimes when i sharpen knives on sandpaper i do it almost parallel to the edge. i notice no difference at all.

 

[ModRQC]

Idk if one of my responses before seemed condescending. It’s a reasonable hypothesis, it’s just that I’ve never seen any blown up image of a knife edge where there was any orientation to the teeth, so I’m inclined to think it doesn’t work like that, and that the way teeth are formed is more like breaking than cutting out uniform grooves. The surface finish on the bevel can be oriented, but idk if that makes a difference.

@captaincaed, I suspect that the reason pull cuts are easier for you (and most people) on pepper skins is not because of tooth orientation, but rather because body mechanics make it easier to put more horizontal action in a pull cut than in a push cut. So more sawing, less straight down chop.

Didn’t have you in mind although I remember you didn’t agree, but you had just formulated an opinion based on logic - the same as you just did. And I’d tend to agree with you for tooth orientation - that there’s not because it’s a break pattern. However the scratch pattern on the bevel I suspect plays a role. When looking at a blown up edge, of course the bigger teeth pattern of ridges and slopes is way bigger than the grooves of the scratch, however all along those bigger teeth there are a lot of smaller teeth, most of them more or less the size of the grooves, and initiated by the grooves. So yes, things like retention and all, it's the bigger teeth that make for most of the perceptible behavior, but I'd guess the scratch pattern does play a role. And even as you refine, the ratio is somewhat kept intact: the bigger ridges and slopes are reduced in size, the smaller teeth also, and the scratch pattern also.

So while it's difficult to imagine the effect of such microscopic factors, I'd say it could be somewhat of a mistake to rule them out altogether?

Edit: application might be important. I mean, kitchen edges, don't think we have to care so much. But something that comes to mind, and I'm just throwing that in the mix without any science backup, is that folks honing razors do seem to mind with getting a perpendicular to edge pattern. Is it a function of size and profile flatness making it easy to sharpen this way, is it something important for geometry maintenance, IDK the science of honing razors... but I wonder if sharpening a razor at an angle like we do a knife, the shave would be as smooth?

 

[ian]

Yea, I don't know anything for sure. It just seems like most pictures of knife edges that you see look like this.

I don't see how the shape of the apex is related at all to the scratch pattern. Like, if you just look at the bright white line at the very apex, and cover up everything else, you'll never be able to tell which way the scratch pattern is going. So, maybe the knife would feel like it's going through food better if your slicing motion is more parallel to the scratches, because of less friction or something on the surface of the bevel, but it just seems unlikely to me that in the picture above, any difference would have anything to do with the apex. Also seems like the effect of the bevel scratches will be pretty small (like, not noticeable at all) if the bevel is small and the grit is reasonably high.

That said, I did see this picture in the last science of sharp post, which is really different. This is apparently K390 steel from a Spyderco knife sharpened on a coarse diamond plate? So idk if this pic has much to do with kitchen knives, but you can sort of maybe see the grooves at the apex here.

 

[inferno]

its buffed i think

 

[ModRQC]

Yea, I don't know anything for sure. It just seems like most pictures of knife edges that you see look like this.

View attachment 142829

I don't see how the shape of the apex is related at all to the scratch pattern. Like, if you just look at the bright white line at the very apex, and cover up everything else, you'll never be able to tell which way the scratch pattern is going. So, maybe the knife would feel like it's going through food better if your slicing motion is more parallel to the scratches, because of less friction or something on the surface of the bevel, but it just seems unlikely to me that in the picture above, any difference would have anything to do with the apex. Also seems like the effect of the bevel scratches will be pretty small (like, not noticeable at all) if the bevel is small and the grit is reasonably high.

That said, I did see this picture in the last science of sharp post, which is really different. This is apparently K390 steel from a Spyderco knife sharpened on a coarse diamond plate? So idk if this pic has much to do with kitchen knives, but you can sort of maybe see the grooves at the apex here.

View attachment 142830

With the first pic I admit it's difficult to see what I meant.

https://scienceofsharp.com/2014/04/16/the-honing-progression/
I'd look at this whole post above; honing progression with a few stones we all use. Side pictures as much as cross pictures. Cross pictures are quite interesting since you can look down on the apex. I still argue that the smaller teeth riding all along the bigger ones are somewhat fit sized with grooves, and that you can see they're born of them too when looking down. It's nothing so clear like one for one, but there's shaping occurring at the apex that's a direct effect of them.

 

[memorael]

I would have to argue it does make a difference if when you use your knife you feel there's a difference. Placebo or whatever, the effect it has on you is what matters. I for one, feel it does make a difference, I like keeping my knives at around 30 degrees relative to the stone since I like making pull cuts more than any other type of cut, and in my experience this angle gives me the best feeling cut.

Try sharpening a knife completely parallel to the stone, that is making the scratches in the same direction as the edge, and let us know what you think.

I am sure someone is going to say, it doesn't make a difference but here's an interesting story, some things aren't perceptible to all. My Shot: Scotty Cameron

 

[ian]

With the first pic I admit it's difficult to see what I meant.

https://scienceofsharp.com/2014/04/16/the-honing-progression/
I'd look at this whole post above; honing progression with a few stones we all use. Side pictures as much as cross pictures. Cross pictures are quite interesting since you can look down on the apex. I still argue that the smaller teeth riding all along the bigger ones are somewhat fit sized with grooves, and that you can see they're born of them too when looking down. It's nothing so clear like one for one, but there's shaping occurring at the apex that's a direct effect of them.

Idk, I can't really see anything like that there either. I mean, a few of the microserrations are in line with the grooves, but it's not clear that even those induce a left or right leaning bias in the shape of the actual apex. Like, you don't see any saw teeth oriented in a particular direction, like people I think are imagining.

 

[inferno]

it doesn't fukn matter.

 

[ModRQC]

Idk, I can't really see anything like that there either. I mean, a few of the microserrations are in line with the grooves, but it's not clear that even those induce a left or right leaning bias in the shape of the actual apex. Like, you don't see any saw teeth oriented in a particular direction, like people I think are imagining.

IDK neither Devil’s advocate here. Thanks for sharing your thoughts again.

 

[Luftmensch]

It just seems like most pictures of knife edges that you see look like this.

If you use scienceofsharp as a point of reference.... Just keep in mind he rose to fame off the back of the straight razor community. So a lot of his images are of hard steel honed at acute angles, with a scratch pattern close to perpendicular to the edge. And... keep in mind 1K (and even 4K) are pretty 'low' grits for razors!

Like I said, I suspect it may have a small to negligible effect for low grit 'toothy' edges - probably less than 1K? Maybe in the 400 range? And only if you have a high 'rake' on the scratch pattern. These images arent well represented in scienceofsharp. I'll admit that this is only an unvalidated hunch, influenced by internet gossip. And is a very weak opinion, other things like angle are far more important! By and large... as @inferno so eloquently put it...

it doesn't fukn matter.

 

[memorael]

Just do the perpendicular and parallel sharpening and cut several things, not just onions and do it for like a restaurant shift, like 2 or 3 cases of stuff per stuff not just 1 or 2 onions and come to conclusions. Experience wise a lot of the things written here on the forums crumble, science explains what is happening not what will happen, so a sharp edge formed using x and y can be a bad edge or a good one, just try it.