Honing angles - is it 8.5 degrees, 17 degrees, or 34?

So in reading Detailed Discussion on Knife Sharpening Angles, which I can't speak to the accuracy of, it seems that these folks are calling what I always thought of as a 20 degree angle 40 degrees. This led me to wonder whether the angles on the razors and knives I use are something altogether different. For instance, my fillet knife and my razors are around 17 degrees, according to my sharpener for my knife (a Lansky) and what I've read about my razors. I wonder if this means that one or both of these is the angle of both sides of the bevel or just from the center point of the blade to one side of the bevel.

Any ideas?

I always assumed that the angle is both sides of the bevel, but I could be wrong.

I can only go by what we found in ONE of the old razor company journals, which said they were aiming at a 17° angle :shrug:

I doubt there is much difference what ya call it other than possible confusion, for new honers, calling it a 16° or 17° angle makes it click with the brain as the razor is sitting on the stone to hone.. You can visualize that angle being correct, and since you only actually hone one side at a time (technically) it seems to make more sense .. Whether it is right or wrong I don't really know but I have read plenety of Knife/Tool sharpening guides that refer to a 22° guide

In any given situation, if there is no standard (and even if there is), it is good practice to define your terms accurately and unambiguously at the beginning. We've certainly done that here. The first thing I see when I open the link you reference is a definition of what they are calling "angle". I fail to see the confusion here: they are referring to half the "razor angle".

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When we tell someone that they should put a 20 degree angle on a knife, we mean that they should sharpen each side to 20 degrees. This creates a total angle of 40 degrees. So when we’re talking about the angle on your knife, we’re talking about the angle at which you hold the knife to your stone.

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Does your "Lansky" system define what it means by angle? Perhaps that is where the confusion sits, because AFAICT that link you posted is very clear.

James.

The link is clear; I am questioning whether we are referring to 17° for both sides of the bevel or for one side when talking about razors.

I am surprised because I didn't realized some people sharpen knives at 40°, which seems awfully wide to me. It got me questioning what sharpening a knife at 20° actually means - the angle of both sides of the bevel or just one. I always thought it meant both, but the link seems to suggest one.

We refer to both: when you look at the formula we give to people to calculate their razor's angle, it has a "2x" at the front.

James.

If the whole edge of either a knife or razor is treated as an angle, then one of the bevels will be half that total angle.

I think the terms that everyone is looking for is "degrees per side" versus degrees "inclusive".

Many knives come with the factory edge of 30° inclusivity with a 40° inclusive micro bevel.

I would suggest that most people when talking about a razor omit the term "inclusive" because it's just a given what's more it's kind of a non-issue because the angle is dictated by the spine of the razor

It is the total included angle of both bevels that is stated.

Place your razor on a flat surface. Place a ruler on top from blade edge to spine. Check the angle with a high school geometry device and you will measure ~7-10 degrees. Most NEW straight razors will measure in this range. But the total included angle for both angles (the exact impression angle if you cut into a piece of clay) is twice that value. The same is true for knives. If you hold the blade at 20 degrees while sharpening each side then you have a final, total included angle of 40 degrees found on most Western kitchen cutlery.

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Originally Posted by DFriedl

The link is clear; I am questioning whether we are referring to 17° for both sides of the bevel or for one side when talking about razors.

I am surprised because I didn't realized some people sharpen knives at 40°, which seems awfully wide to me. It got me questioning what sharpening a knife at 20° actually means - the angle of both sides of the bevel or just one. I always thought it meant both, but the link seems to suggest one.

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The Angel you sharpen a tool like a knife depends on what it's used for. If ya going to hack away at a tree with a bowie knife or type of cheap knife you do put a 40 degess angle on the tool. With a axe that's being used to spit wood you go with a 40 degree angel.
with a logging axe for chopping down trees you go with a 20 degree angel. or a little less. you can make it a sharper angel if chopping pine.
but being with razors we put electic tape on the spine and let them lay flat on the stone what ever angel it is it must be correct.
so if it shaves nice no worries about doing it wrong.

double edged axes are cool one side you put a 20 degree angel to the blade.
the other you put a 40 degree angel. 40 degree angel side for chopping close to the ground
20 for chopping down trees.
Put the 20 degree angel on you strong swinging side.

Western chefs do a lot of chopping strokes. The 40 degree angle holds up better under those conditions; however, this is also a hold over from when the blades were thicker and the steel not so hard as is available today. Most fine kitchen cutlery today uses superb stainless steel alloys that can be made even sharper by using the Asian (santoku) angle of 30 degrees. This is why so many new "pull-through" style sharpeners are offering both angles. The sharper angle is OK for fine Western cutlery - even for chopping.

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Originally Posted by Suile

double edged axes are cool one side you put a 20 degree angel to the blade.
the other you put a 40 degree angel. 40 degree angel side for chopping close to the ground
20 for chopping down trees.
Put the 20 degree angel on you strong swinging side.

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Sushi knives are sharpened only on one side for similar utility.

Got it. Thanks. I didn't mean to belabor the point; I just perceived ambiguity where I hadn't known any to exist, and looked for a rule of thumb to explain it.

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Originally Posted by DFriedl

Got it. Thanks. I didn't mean to belabor the point; I just perceived ambiguity where I hadn't known any to exist, and looked for a rule of thumb to explain it.

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Yea !!!! now after 15 posts it became clear as mud :(

Not the first time this has come up . . .

http://straightrazorpalace.com/forge...ded-angle.html

A Forum search for "arctan" (a critical part of the formula that relates blade thickness and blade width to the bevel angle) will find all of the many threads . . .

. Charles

you can calculate the angle using simple geometry.