Edge Profiles (not types)

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atavist

atavist

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Content removed as thread was not productive.

Mod please remove.
 
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Hollow, flat, scandi are edge grinds..... as in the shape of the beveled area...

I'm talking about the geometry/amount of area beveled... not how that area is ground.

a blade could be Underground with a flat grind/convex edge, or hollow ground, or full flat/scandi ground.
 
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He is talking about the where the grind lines are. High, low, full.


number three does make for a nice looking blade, but done like shown it will make for a very thin tip, especially on a hard drop point or sheepswharinsingo thingymagig.

A very high number 2 mixed with some 3 would be my preferred style.

edit: 4 means you screwed up. :D
 
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lets not hijack the thread... technically a scandi grind is flat all the way to the edge.... so a micro bevel makes it not a scandi grind

... ok, back on topic.

what profile do you guys like? and why?
... did i miss anything in my discussion?
 
The real question is, how do you get a nice radius in your grind termination when shooting for a quite high grind line.(plunge line) Do you want a plunge line to go straight up? Angled up forward but straight? Radiused?

Should a grind line follow the belly and curve with it, like it? Should it be flat like a ruler to the tip or should it angle up or down no matter the belly?
 
ev13wt said:
The real question is, how do you get a nice radius in your grind termination when shooting for a quite high grind line.(plunge line) Do you want a plunge line to go straight up? Angled up forward but straight? Radiused?

Should a grind line follow the belly and curve with it, like it? Should it be flat like a ruler to the tip or should it angle up or down no matter the belly?
Click to expand...


you lost me on the first part... my grind terminations (and all I've seen) just leave a chine in the blade.. the chine can be hard (crisp) or soft (rounded)... the angel of the plunge is not functional just aesthetic... I like a straight plunge, to slightly upwards, but with radiused shoulders, (i.e. sanded off a bit, not too crisp as once again I believe that makes a stress riser... though a lot like it as a mark of precision and most production knives have them)
 
I personally prefer grind #2 with a zero ground chisel edge (other side flat) and a tiny, 0.2-3mm wide microbevel.

I wouldn't call it "under-ground" per se. Maybe on thicker blade stock it would make cutting performance suffer.
 
OP: Just for my own understanding, you say "edge grind" so when you want to or need to resharpen the edge and you want to maintain the original angle, you would have to pretty much lay the edge grind flat against the sharpening stone? So for #4, with every resharpening, you're even thinning out the whole blade?

ETA:
re: your statement for Type 1: "This edge is very common in production knifes for a simple reason. It minimizes stock reduction, ergo material cost."
I don't see how #1 is associated is minimizing material cost if that is what you mean. You already paid for the material. You're not going to save money by reducing the amount of stock you remove. What you may save is the machine or labor cost to remove incremental material above the minimum. As a matter of fact, if there is any salvage value in the material removed, minimizing material costs may be more associated with Type 4.

If you're saying you can save on material cost with Type 1 because you can start with thinner stock, then you're not using a fair comparison. A fair comparison would dictate that all other attributes of comparative samples are the same except for the attribute you are analyzing which, in this case, is the edge profile.
 
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Rey HRH said:
OP: Just for my own understanding, you say "edge grind" so when you want to or need to resharpen the edge and you want to maintain the original angle, you would have to pretty much lay the edge grind flat against the sharpening stone? So for #4, with every resharpening, you're even thinning out the whole blade?

ETA:
re: your statement for Type 1: "This edge is very common in production knifes for a simple reason. It minimizes stock reduction, ergo material cost."
I don't see how #1 is associated is minimizing material cost if that is what you mean. You already paid for the material. You're not going to save money by reducing the amount of stock you remove. What you may save is the machine or labor cost to remove incremental material above the minimum. As a matter of fact, if there is any salvage value in the material removed, minimizing material costs may be more associated with Type 4.

If you're saying you can save on material cost with Type 1 because you can start with thinner stock, then you're not using a fair comparison. A fair comparison would dictate that all other attributes of comparative samples are the same except for the attribute you are analyzing which, in this case, is the edge profile.
Click to expand...

Per the first part the profile has little to nothing to do with the grind... most #4s are primary flat grinds with some kkind of secondary edge... not necessarily a true scandi

For the second..
As a maker material is not just the original bar stock to me...
... should have been more specific... profile 1 Saves on end mills, belts, and most definitely labor. .. I consider those all "materials"
 
atavist said:
Per the first part the profile has little to nothing to do with the grind... most #4s are primary flat grinds with some kkind of secondary edge... not necessarily a true scandi

For the second..
As a maker material is not just the original bar stock to me...
... should have been more specific... profile 1 Saves on end mills, belts, and most definitely labor. .. I consider those all "materials"
Click to expand...

For the first part, thank you for clarifying. In that case, for the most part, I think it's simply aesthetics besides the obvious trade-off between mass and ability to slice. One can take the extreme cases for initial blank thickness from being very thin and being very thick and compare the profiles within the same thickness. On the other hand, one can make a case that #1 profile with an initial thin blank would have better slicing ability than a #4 profile made from an initially thicker stock. Hence, one can say one can arrive at the desired slicing / minimal stress risers condition by also varying the initial thickness. If one can arrive at a target slicing / minimal stress riser condition by mixing and matching variables such as initial thickness, edge profile, (not to mention steel make up), then I think it supports my belief that it comes down to aesthetics.

For the second part, as a manufacturing professional, the standard as you know is that material is divided into direct and indirect material. And when people talk about "material," the consensus is they are talking about direct material - the material that is part of the product. To refer to indirect material as simply "material," the context ought to be laid beforehand which, in this case, it was not.
 
Bad termanology makes this thread confusing.
 
Rey HRH said:
For the first part, thank you for clarifying. In that case, for the most part, I think it's simply aesthetics besides the obvious trade-off between mass and ability to slice. One can take the extreme cases for initial blank thickness from being very thin and being very thick and compare the profiles within the same thickness. On the other hand, one can make a case that #1 profile with an initial thin blank would have better slicing ability than a #4 profile made from an initially thicker stock. Hence, one can say one can arrive at the desired slicing / minimal stress risers condition by also varying the initial thickness. If one can arrive at a target slicing / minimal stress riser condition by mixing and matching variables such as initial thickness, edge profile, (not to mention steel make up), then I think it supports my belief that it comes down to aesthetics.

For the second part, as a manufacturing professional, the standard as you know is that material is divided into direct and indirect material. And when people talk about "material," the consensus is they are talking about direct material - the material that is part of the product. To refer to indirect material as simply "material," the context ought to be laid beforehand which, in this case, it was not.
Click to expand...

Both excellent points.
 
Jason B. said:
Bad termanology makes this thread confusing.
Click to expand...

Sorry about that.
Terminology is always a hard one...
That's why I posted the blurb here before putting it on my site. A lot of customers like knives but don't know what they want. So I want to provide some information pages to help them make desicions...this is an area where I get a lot of "whatever you think is best" but i prefer the customer make their own educated decisions... I can choose one for function purposes but if they don't like it aesthetically ...

Hopefully by the time this thread dies we can have clear unconfusing little blurb that I can direct them to to help make a decision.

Thanks for your input guys.
 
Sooo...
1) VERY low saber
2) Mid/nominal saber
3) High saber / full-grind
4) Full Flat Grind.

Why not stick with common terms?

In answer to preference, stock thickness is the main determinant for me.
Scalpels and utility blades (and disposable razor-blades) as well as some kitchen knives use #1 effectively due to very thin stock that doesn't impede penetration/cutting and maintains maximum blade stiffness with a ~20-degrees inclusive grind angle.
Double the stock thickness to get 8X the stiffness for increased leverage, but then wedging starts to cause issues so the primary grind needs to be taken down to <10 degrees per side, i.e. make it wider, with an edge-bevel added for increased durability at the apex.
 
chiral.grolim said:
Sooo...
1) VERY low saber
2) Mid/nominal saber
3) High saber / full-grind
4) Full Flat Grind.
Click to expand...

Those terms I understand immediately. But I'm going to run my own terms up the flagpole and see who salutes:

1) Ol' Betsy grind
2) Tango whiskey grind
3) Banana puddin' grind
4) Extreme inverse hollow grind

Work for anybody?
 
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