30 degree shave angle pet peeve

[bluesman 7]

OK I agree that new shavers tend to shave with too high of a shave angle.

How many times have you seen this advice; 30* is too wide. You want to have the spine of the razor within one, two at the most, spine widths of your face.

Well, one spine width away from your face puts the axis of the blade at 26 degrees and two puts it at 48 degrees!

 

[Seraphim]

The mental imagery of a 30 degree angle is what tends to cause the issue.

Yes, if you lay the blade flat on a hone, the axis is already lifted ~8 degrees (for a 16 degree bevel angle), add one spine width (again, 16 degrees) and you are at ~24 degrees, as you said.

But most folks come to this party with the idea that flat to the face= 0 degrees, and then add 30 degrees to that, and that seems to be where the issues come in.

The advice should read "have the razor almost flat against your face" and leave it at that, in my opinion.

 

[Lmarkow]

I guess I'm "guilty" of whatever the accusation is here. And I must also confess that I have no idea what you mean by "axis of the blade." Is that the center of the spine?

I just shave with these things. I try to keep the edge of the spine closest to my face within a spine or two. Is this incorrect?

 

[bluesman 7]

I guess I'm "guilty" of whatever the accusation is here. And I must also confess that I have no idea what you mean by "axis of the blade." Is that the center of the spine?

I just shave with these things. I try to keep the edge of the spine closest to my face within a spine or two. Is this incorrect?

You are shaving correctly and in strict terms using a shave angle of about 30*

 

[bluesman 7]

My peeve is that everyone quotes this 30* is two steep rhetoric, and then gives a method of establishing the correct angle that results in ~30*

 

[bluesman 7]

The advice should read "have the razor almost flat against your face" and leave it at that, in my opinion.

Yes, if we all switch to this advice, I will need to find something else that drives me crazy.

 

[rajagra]

Doing the (sad) maths, if the bevel angle is 16°, raising the spine off the skin by:
1 spine width: rotates the blade by 16.2° (total razor angle 24.2°);
2 spine widths: rotates the blade by 33.8° (total razor angle 41.8°);
3 spine widths: rotates the blade by 56.6° (total razor angle 64.6°)

The further you move the spine, the more rapidly the problem grows.

 

[Lmarkow]

Sorry, these numbers don't mean much to me. I can't even make the little degree symbol. What is the angle created between my face and the side of the spine closest to my face and the edge point? That's what I refer to.

 

[flashover604]

Where IS that little degree symbol? I'm serious. I use an iphone or iPad and can find that rascal.

Now, back to your regularly scheduled pet peeve.

 

[global_dev]

Where IS that little degree symbol? I'm serious. I use an iphone or iPad and can find that rascal.
.

i assume you meant "can't"..

ios hold the 0 key

on osx -

Option + Shift + 8 is Degree
Option + k is (spacing) Ring Above diacritic
Option + 0 is the the Masculine Ordinal Indicator (has a line under it in some fonts)

 

[flashover604]

Yep, I meant can't. I'll blame Siri.

° well look at that. Now I need to go make a bunch of posts taking about how it's x° outside do I can try out my new symbol! Thanks for the info!

 

[Big Mike]

Doing the (sad) maths, if the bevel angle is 16°, raising the spine off the skin by:
1 spine width: rotates the blade by 16.2° (total razor angle 24.2°);
2 spine widths: rotates the blade by 33.8° (total razor angle 41.8°);
3 spine widths: rotates the blade by 56.6° (total razor angle 64.6°)

The further you move the spine, the more rapidly the problem grows.

I'm not very experienced in straight razors but wouldn't the angle numbers you have calculated vary dependent to the width of the spine, which in theory is variable? Again I'm new or are you just tying to give us a numerical visual of the unproportional increase in angle. I think I may have lost you here.

 

[global_dev]

Angles are dependent on the lengths, so it shouldn't matter

 

[Big Mike]

Angles are dependent on the lengths, so it shouldn't matter

yes but isn't the discussion about moving the blade away from the face equal to the width of the spine? It seems to me then the reference should be to the blade which would again add a variable difficult to judge.

 

[global_dev]

The spine width correlates with the length to make the angle so a spines width is directly related to tbe angle. Maybe im missing something.

As the the length increases, the spine increases but bevel angle stays same. So the spines width is a good value if you have a good angle.

 

[Seraphim]

yes but isn't the discussion about moving the blade away from the face equal to the width of the spine? It seems to me then the reference should be to the blade which would again add a variable difficult to judge.

Wider blades (7/8s, 8/8s) tend to have broader spines, but that is simply due to extending the very same (roughly speaking) 18° angle as a 5/8 blade with a narrower spine.

 

[rajagra]

Sorry, these numbers don't mean much to me. I can't even make the little degree symbol. What is the angle created between my face and the side of the spine closest to my face and the edge point? That's what I refer to.

That's an important point. I think when people talk of a 30° angle they are referring to the absolute angle of the razor relative to the plane of the face, not how far the razor is rotated away from the face from the "flat" position - which isn't parallel!

Does this help? Picture shows razor with 16° bevel, and is to scale...


The important point is that even one spine width out is pretty steep. Two widths out is borderline crazy.
Also note that even when completely "flat", the blade edge is pointing into the skin and can dig in (to both hair and skin.)

 

[Lmarkow]

I think what people who hone razors mean when they talk angles is different than those who don't. If the questioner is asking the question in the shave clinic, which way of looking at this is likely to be more helpful?

Very helpful picture, though.

 

[bluesman 7]

Nice drawings Ray. Very helpful.

 

[rajagra]

I think what people who hone razors mean when they talk angles is different than those who don't. If the questioner is asking the question in the shave clinic, which way of looking at this is likely to be more helpful?

We just don't know. My intuition is to think of the axis of the blade (through the centre) but clearly other people think of the angle of the gap.
But if we talk about moving one spine width away from the face, that is at least unambiguous.
Better yet...

The advice should read "have the razor almost flat against your face" and leave it at that, in my opinion.

P.S. If we talk about angles, someone shaving will most likely use the sticking-out scales as their guide, I think. The blade itself is just too darn small to judge angles from accurately.