Let's Talk Bevel Angle

[Frank Shaves]

I will start. I recently picked up this "bad" little Union Spike 9/16* near wedge. Looks like it has never been used and still has its factory edge, so before doing anything I decided to measure the bevel angle and came up with 16.44 degrees. I measured a bunch of razors multiple times each to build my confidence in measuring the hypotenuse. Just for fun, let's call the bevel angle of this razor 16.5 +- 0.5 degrees. I have to believe that the folks in Olean, NY designed and intended this razor to have a bevel angle around 16.5 degrees, and never even thought about a bunch of guys putting layers of tape on the spine, so my plan is to first put this baby on my Naniwa 12k without tape (or perhaps with one layer of Kapton) to try to preserve the factory bevel and experience what the makers intended. I am also wondering if Union designed their razors to have different bevel angles based on the grind.

Comments are appreciated.

*The box says 9/16, but I measure the hypotenuse between 9/16 and 5/8.

 

[stone and strop]

It seems different mfg's used different angles perhaps even varying for grinds within the line up.
I've always found Bokers to be crazy lean. I just measured an Edelweiss that came in at 14.7.
As you can imagine it produces an incredible edge but does not retain it for the same amount of time as some others.
After having honed many hundreds of razors over 19 years I almost never measure the angle of one I pick up.
People are obsessed with it like it will make a razor unusable being???.
If the razor does not look right off the bat, of course I would investigate via some measurements.
Some are lean, some are heavy, they can all shave great unless they are on the outset of plus or minus.
When they are - they look it and feel like it, at least to me they do.

This is another reason why I recommend for someone learning to hone to use a layer of tape till they sort things out.
Imagine someone starting with this razor and taking too much off the spine making it sub 14. It would be catastrophic.

 

[bluesman 7]

I'm an angle fanatic and virtually never hone without measuring the bevel angle. The only way I would not measure it is if i didn't have the measuring tools handy. This is just a thing with me and I wouldn't argue that anything bad happens to people who don't measure their angles. Though the measurement does influence how I hone.

By the way I don't even need a calculator or trig tables to measure the angle. Spine thickness/Active width X 57.3 degrees = ___ degrees. There is a mathematical error introduced by using radians this way because the spine thickness should be measured on the arc instead of a straight line, but the error at these small angles (around a tenth of a degree) is negligible.

 

[DrStrange]

I used to measure my razors after I honed each one for the first time.
I got a feel for the difference it made and eventually I stopped.

I just recently honed and used a couple of Torrey s : a Monogram and a 136.
I recognized the problem with the Monogram.
The blade was smooth and the shave was BBS, but it didn't feel right.
I measured it at 19.1 degrees. It's out of the rotation.

One of my favorites had a cutting angle of 14.9 and it held out for a few shaves.

I have a lot of razors waiting to get into the rotation
so I'll retire any of them at the first sign of imperfection.

There are 3 razors that have been in the rotation since before the time when I started retiring razors.
Boker Red Injun 102 - 16.3 degrees
Heljestrand MK 31 - 18.2 degrees
Heljestrand no model - 17.2 degrees

I have a Case Temperite 25 which seems to be holding up well at 15.2 degrees.

The other Torrey, the 136, I liked a little better and kept it in the rotation. 18.9 degrees.

The accuracy of the measurements is just whatever comes from my best efforts.
I'm sure that all of them are off by unspecified varying amounts.

 

[Darth Scandalous]

I think I've mentioned it before. I have an Engström shoulderless that has a ridiculously skinny spine. Bevel angle is under 13 degrees throughout the length. It holds an edge pretty well except for near the toe (where the blade is widest and the angle is lowest). I recently rehoned it with 2 layers of tape to see what it would do. Honestly I liked the shave better before but maybe it needs a little more attention. Regardless, it probably needs the increased angle to keep the toe from getting crumbly.

I have a Russian Ekstra that is 15 degrees, maybe under. I don't have it written down. It's also very thin. But it holds an edge and shaves great.

At the other end of the spectrum is a Dahlgren frameback that is nearly 20 degrees. Doesn't affect the shave as far as I can tell. The rest are in the 16 to 18 range with most of them closer to 16.

I don't worry about it unless the edge is consistently harsh or has a tendency to chip. Then I might consider bumping up the angle a degree.

 

[rbscebu]

I started SR shaving with blades having a bevel angle of about 18°±1°. I enjoyed shaving with them. Later I enjoyed a little more shaving with angles of about 16°±1°. As my honing and SR shaving technique developed, I have found that I equally enjoy shaving with all bevel angles from about 15° to about 19°.

After all, SR shaving is all about enjoyment.

Edge longevity does not come into it for me as I maintain my edges on a 0.1μm diamond pasted hanging balsa strop after each shave.

 

[Frank Shaves]

I think I've mentioned it before. I have an Engström shoulderless that has a ridiculously skinny spine. Bevel angle is under 13 degrees throughout the length. It holds an edge pretty well except for near the toe (where the blade is widest and the angle is lowest).

Perhaps the Engstrom is made from Swedish steel and that plays a part.

 

[Darth Scandalous]

I

Perhaps the Engstrom is made from Swedish steel and that plays a part.

I'm pretty certain it is made from Swedish steel but I know what you mean.

This thread inspired me to pull that Engström out and reset the bevel with only one layer of tape. I'd rate it only moderately hard on the spectrum of Swedes in my care. I ran out of time but it's got a nice 1micron edge at the moment. Needs a little more polish in a couple spots, then I'll put it on the translucent ark.

 

[Tomo]

My best shavers are between 17 and 17.5 degrees.

 

[rbscebu]

My best shavers are between 17 and 17.5 degrees.

It varies for each person based on their whiskers, skin, blade, steel, shaving technique, etc..

 

[Gamma]

I have not run into a razor with a 20 degree bevel that didn't shave better when the angle was reduced to 16-17˚.
Obviously, a stout bevel will shave. How it shaves for someone depends on a ton of variables specific to that person. Most of those variables here in my home are fairly well 'fixed' at this point in time. Comparisons, for me, are easy to establish and over time it is obvious that fat bevels do not suit me well and more acute bevels do better for me.

A difference between 20 and 19 degrees might not be noticeable but 20+˚ to sub 17˚ is a remarkable difference. I could have lidocaine filled cheeks and tell there's a difference, the audible feedback alone is enough to raise eyebrows.

A steeper angle will allow a thinner edge width and that is a major criteria in establishing overall sharpness. It's not the only factor though, so to reap the benefits of that skinny dimension, the rest of the ducks must be in a row. Easier said than done. Some people won't care - or notice - doesn't mean the benefit isn't available though. It's just shaving so whoever likes what, or chooses to roll with what, is just fine. If someone enjoys a 20 degree bevel, that's fine by me.

Factually, not everyone wants to grind down a spine to achieve a better angle. For, all fo this really is/was an 'ignorance is bliss' scenario for me - unless I spent time comparing bevel angles in many razors, I wouldn't know, and probably wouldn't care. Knowing the differences, having experienced them, and being able to make a razor shave better; are both blessings and curses.

Qualifying 'better' - cutting efficacy is notably increased, shaves are closer, shaves last longer, smoothness is enhanced.

I have noted that some of the softer Sheffields might not take a great edge at sub-16˚ and I might believe that the edges they do take at those angles will 'fall off' faster than one made with a more obtuse angle. More often than not, cheap steel shows tendencies toward chipping and microchipping at steeper angles. The incidence of edge issues increases as the angle decreases.
I have a fairly old Greaves on my bench that has a pretty steep angle compared to how it arrived; it's got a ton of shaves on it and goin' strong.

 

[bluesman 7]

If the usable bevel angle is viewed as a continuum where below X degrees is too harsh and above X plus some number of degrees is too obtuse to shave well. It is inconceivable that edges taken from close to these two extremes would shave with the same character.

 

[Eastcoast30]

FWIW: As bevel angle decreases, edge retention decreases. So I am thinking some of those hard Swedish steels will fare better with a smaller bevel angle.

 

[Tanuki]

Spine thickness/Active width X 57.3 degrees = ___ degrees

This formula is fast enough to get me calculating bevel angles, at least for some favorite razors, problem children, and reformed problem children. And for my as yet unused Rolls wedge blades.

Will it improve the closeness of my shaves? Nothing is going to make SR sideways passes at the base of my neck possible. Good thing I've got about as many hoe razors as SRs. My neck maelstroms are the ultimate closeness test for m shaves.

Fine tuning edges even further might make shaving my upper lip easier, but I'm too fond of my mustache to ever shave the lip often enough to find out. And the rest of my face is not presenting any closeness issues when closeness is what I'm targeting.

Truth be told, shaving is most often about testing and extending my tools and technique in honing, restoration, edge maintenance, and razor use and care. Knowledge and Science! Getting stubble off is a byproduct.

If shave velocity and quality were my primary goals, I would cut my SR choices from dozens down to a minimum and get some consistency. But for me, honing and shave time is play time.

So bevel angles will just be some input into my honing practice. If the input seems useful, I'll keep measuring away. If not, I probably will let it go.

 

[Tanuki]

Edge longevity does not come into it for me as I maintain my edges on a 0.1μm diamond pasted hanging balsa strop after each shave.

If this is general experience, I guess I would have to give up diamond/balsa in order to fully explore the edge longevity spectrum. I have great respect for my diamond balsa progression, though I hand hold rather than hang those strops.

Does anyone here find distinct effects of bevel angle on stropping vs honing?

 

[Darth Scandalous]

FWIW: As bevel angle decreases, edge retention decreases. So I am thinking some of those hard Swedish steels will fare better with a smaller bevel angle.

This is kind of a tangent, but sometimes I wonder about the blanket statements we hear about hard Swedish steel. I've only owned 11 Swedes, six makers, and no way to measure them scientifically, but based on honing etc most of them seem to be a little harder than average compared to the rest of the crowd. But, a couple of them are ridiculously hard. The older ones seem harder than the newer for what it's worth.

They're all over the map in terms of bevel angle too. One of the hard ones is the neat 20 degree Dahlgren I mentioned. Not particularly interested in trying to hone off the spine to reduce it. It takes whiskers off as well as the others, jusy doesn't feel the same while doing it.

 

[bluesman 7]

Does anyone here find distinct effects of bevel angle on stropping vs honing?

I think a lot depends on the micro structure of the steel. I have a razor honed to 15.5 degrees that has 166 shaves and counting on just clean strops, though I think that there is a lot of luck involved with this longevity. Most of my other razors with similar angles and micro structure end up getting honed in the 60-120 shaves range. I don't have any data points for angles very much more obtuse as I don't enjoy them enough to put in the shaves to find out.

 

[2bit_collie]

From knife honing I absolutely believe that a narrower bevel angle should give a sharper edge. Though in fairness the range of angle is much broader for knives than for razors. For straight razors I have not really seen this. I do measure the bevel angle of every razor I acquire, as part of my documentation process. Everything is between 15-20 degrees. If I were to pick my favorite straights to use they would be all over that range. In particular my Japanese razors tend to run fat (I think I average almost 19 degrees across 5 razors) yet they all shave superbly. Would they shave BETTER if they were down at 17 degrees? That seems logical. But I don’t have the experience others have with taking down the spine width to get the narrower bevel angle.

 

[Tomo]

19+ and the edge starts to feel a little dead to me. Just not as lively as I’d like it. To some extent you can counter this with a keener finish.

I wonder if razor manufacturers intentionally start on the higher end of the spectrum knowing that most people will wear the spine more than the edge. Starting a little fat ensures that the razor stays within an ideal range throughout its life. Just a thought.

 

[rbscebu]

From knife honing I absolutely believe that a narrower bevel angle should give a sharper edge. Though in fairness the range of angle is much broader for knives than for razors. For straight razors I have not really seen this. I do measure the bevel angle of every razor I acquire, as part of my documentation process. Everything is between 15-20 degrees. If I were to pick my favorite straights to use they would be all over that range. In particular my Japanese razors tend to run fat (I think I average almost 19 degrees across 5 razors) yet they all shave superbly. Would they shave BETTER if they were down at 17 degrees? That seems logical. But I don’t have the experience others have with taking down the spine width to get the narrower bevel angle.

The width of the bevel angle does not affect the cutting ability of a SR. Consider a true wedge SR. The whole blade face both front and back is the bevel, if honed flat.

As for preferred bevel angle, I find that it has little bearing on the shave quality. For me, a more acute bevel angle (down to about 16°) is keener and a more obtuse bevel angle (up to about 19°) is more forgiving, although all shave perfectly for me.