Thread: bevel width

Originally Posted by ferroburak

Ok let me put a crude classification here:

Hollowness:
full wedge:A
1/4 hollow:B
1/2 hollow:C
full hollow: D

blade width:
15 mm(or 5/8) = a
18 mm (or 6/8)= b
20 mm (or 7/8) =c
25 mm (8/8) = d

So what edge width should a "A-b" razor have? What about others?

I think this is quite impossible to set figures to.
The reason I feel that way is that you are missing a key element here, and that is spine width. Geometrically that will be one of the determening factors.
As an excample I have different razors in the same width and grind with very different bevel widths due to varying spine widths.

Originally Posted by Birnando

What I mean is, given a constant spine width, the bigger the blade is, the wider the bevel becomes. Bigger blades in this context meaning wider. E.g. a 4/8 vs 8/8, the bevel on the 8/8 will be wider than the one on the 4/8, if the spine width and grind is constant.

Hi,

Ok I see now. But a 8/8 wouldn't have twice the width of a 4/8.

How can I formulate it?

Originally Posted by Birnando

I think this is quite impossible to set figures to.
The reason I feel that way is that you are missing a key element here, and that is spine width.


Geometrically that will be one of the determening factors.
As an excample I have different razors in the same width and grind with very different bevel widths due to varying spine widths.

I assumed blade spine thickness varies so as to keep the bevel angle at a constant value, say 17 degrees.

Hello,

assuming your talking about the width of the bevel that creates the cutting edge... only in the wedge does the grind matter, in a true wedge the bevel wedge would be the entire width of the blade, unless you use tape. For other grinds the bevel width mostly depends on spine thickness and how wide the blade is, which determines how much metal would be removed to create the "cutting bevel". the grind does make some small difference but only noticeable when you get into the "wedgies".

Or is this question about what width of blade corresponds with the grind?, for example 4/8th for wedge, 5/8 for quarter hollow, 6/8 for 1/2 hollow? I don't think that matters.

there are 3 variables in your question so i'm not sure which one to base my answer on,
I would love to know what your thinking so please restate your question?

Originally Posted by ferroburak

No,

I assume that blade spine thickness varies so as to keep the bevel angle at a constant value.

In my experience, your assumption here would be wrong.
There are slight differences to the angle of the bevel.

As an example, add a layer of tape, and what you get is a narrower bevel and a more acute angle on it.
Minute difference for sure, but it is there, and that's how it is with different razor models as well. No absolute angle they all use as far as I know.

I hope I am understanding you correctly here, not trying to argue at all, just trying to help, and to understand correctly.

Originally Posted by Birnando

In my experience, your assumption here would be wrong.
There are slight differences to the angle of the bevel.

As an example, add a layer of tape, and what you get is a narrower bevel and a more acute angle on it.
Minute difference for sure, but it is there, and that's how it is with different razor models as well. No absolute angle they all use as far as I know.

I hope I am understanding you correctly here, not trying to argue at all, just trying to help, and to understand correctly.

Hi,
The angle is around 15 degrees so let's keep it constant in order to simplify/model the problem. Thanks for the help.

Ok i think i am getting slowly what you are trying to ask.
i think you are trying to find out the best spine to edge angle.
which is between 16-20 degree and if am not mistaken 16,5 is the best.
Now putting in bevel in to conversation will confuse a lot of us at least me.
Bevel could be wider or narrow has nothing to do with sharpness of the cutting edge.
hope i am helpful.

Originally Posted by ferroburak

I assumed blade spine thickness varies so as to keep the bevel angle at a constant value, say 17 degrees.

Yes this is correct.
wider the blade thicker the spine in simple words?
as you hone your wear down spine and the edge same time.
angle stays same.

Originally Posted by 111Nathaniel

Hello,

assuming your talking about the width of the bevel that creates the cutting edge... only in the wedge does the grind matter, in a true wedge the bevel wedge would be the entire width of the blade, unless you use tape. For other grinds the bevel width mostly depends on spine thickness and how wide the blade is, which determines how much metal would be removed to create the "cutting bevel". the grind does make some small difference but only noticeable when you get into the "wedgies".

You got my question correct but I disagree that the difference is small.

I'm well aware that my question is hard to answer and also depends on steel type, shoulder type and personal preference. I nevertheless believe, if bevel width is in question, other parameters are insignificant compared to blade width-blade grind.

Maybe it would be best to start with my second question. Taking other variables constant, how wide a bevel would you put on a "A-b razor" as described in posts 1&7?

Thanks for the all help.