Thread: Can a razor be too sharp?

Let's say that .5 microns is the keenest that a razor can be honed to.

I think that we can agree that a linen strop is designed to catch and remove corrosion and oxidation, and the leather is used to align the blade.

Given that some metal is removed in stropping, albeit a negligible amount, it would seem that:

1) Stroping is only further sharpening the blade.

2) Given the proper techique it would not be possible to over strop.

Originally Posted by Bladerunner

Let's say that .5 microns is the keenest that a razor can be honed to.

I think that we can agree that a linen strop is designed to catch and remove corrosion and oxidation, and the leather is used to align the blade.

Given that some metal is removed in stropping, albeit a negligible amount, it would seem that:

1) Stroping is only further sharpening the blade.

2) Given the proper techique it would not be possible to over strop.

CrO2, for example, is a considerably more mild abrasive than diamonds. When you strop with CrO2, the scratches are not going to be as deep as using a stone, nor will it necessarily reduce the edge's overall sharpness. Depending on the final grit you sharpen to, the CrO2 can polish the grooves at lower grits, making the knife feel smoother and "sharper". If you strop after higher grits, it can compliment what the slurry or nagano stone paste on the stone does.

IMHO, polishing the bevel is what makes the razor sharp in the first place. The second the two sides of the bevel meet, EVERYTHING you do from that point forward could be considered polishing the bevel. They can meet at VERY low grits. I think, though, that you are defining "polishing the bevel" as starting the second that you have made some portion of the edge as sharp as it's going to be (0.5 micron assuming that number is correct).

So, I'll jump on board with that argument then, that around the 4k level I will assume (I have no proof) that you are starting to get into the realm of "some areas of the edge are as sharp as they will get."

So, think about it like this. At the 4k level, you have two sides of the bevel, both with scratches in them, meeting up to form an edge. As far as I can tell, the scratches in these two edges of the bevel cause the two sides to not meet up as evenly where they meet (the edge). Since each side of the bevel is basically varying in width from having scratches, the very edge is varying in width also. The complete edge would look jaggedy in width (on a microscopic level) if viewed straight on. That is to say, the edge may be 0.5 microns (or whatever the sharpest they can be is) at some points, and, say 2 microns at others. Where the two valleys of the scratches meet perfectly, it might be the perfect 0.5 microns in width, but where two peaks of the scratches meet, it is wider, say 2 microns (just making up that number). Does this make sense? I wish I could draw a picture to describe what I'm saying.

Anyway, as you take these scratches out further and further (polish), the edge becomes more and more consistent in width. Just for the sake of argument I'm going to pull some numbers out of the air, assuming that your 0.5 micron width is the sharpest a razor can get. Anyway, let's say that at the 4k level, the edge varies between 0.5 microns and 2 microns in width. Some points where the scratches on both bevel sides meet perfectly are as sharp as possible (0.5 micron), but where the scratches do not meet perfectly, you have varying edge widths as wide as 2 microns. Now, you move on from the 4k to a finer stone. Now you are removing the 4k scratches with 8k ones which aren't as deep. Now the edge varies in width from the same perfect 0.5 micron to, let's say, 1.5 micron at the spots where the scratches "meet up" the worst. Then you move on to say a 12k stone, and now you are varying between, say, 1 micron and 0.5 micron. Then you go to a 16k and get to 0.8 micron and 0.5 micron. Then you get to say, a 30k hone and now you much closer to a consistent 0.5 microns because the scratches are so thin that you really can be very consistent.

Now, these numbers are completely made up to try to illustrate what I'm thinking, but does that make sense?

If you subscsribe to this making sense, then I would argue that as you polish the edge, you are making it a more consistent width that is closer to as sharp as it can possibly get. When the edge is more consistent and also a smaller width, it will cut better. If it cuts better, I define it as sharper. Therefore, polishing makes it sharper.

Or I could be completely wrong, but it makes sense in my head anyway.

I totally agree (and actually follow) your thinking here! I had this very epiphany last week (without reading this thread), and posted it on my blog. To take your thought one step further, if you spend too much time on the final stone, you will again end up with an uneven edge because you have established those high and low points on the blade.

How many strokes does it take? We'll have to ask the tootsie pop owl (he'll say 3)

I don't think a steel straight razor can be too sharp to comfortably shave with. It can be too rough possibly, but not too sharp. Sharp is sharp enough to cut skin, but the edge needs to be smoothed and technique needs to be such so that the razor is not asked to dig into the skin

I have found that razor can be sharp and rough which gives it the appearance of being sharper than it really is. I use to go down to 0.25 diamond paste and they were very sharp but they were not smooth and the edge would not hold on for more than about 4 or 5 shaves. I would imagine that my beard was breaking off the "spikes" caused by the diamond paste. I found that once I went to Chromium after the diamond paste the edge became very smooth and would last a good week before I lost a little performance. I also started getting shaves exceptionally smooth. To sharp? Well I started getting a lot of weepers and even when I lightened up the pressure it was a challenge.

Take Care,
Richard

i would say yes it could be.
i have TI and used almost a year
i love this blade. recently i got crazy and said will get this blade sharpest edge it could take.
i usually shave every other day.
i sharpened TI and shaved i feel it is a lot sharper then what i use usually but problem i got after 2 days. My face didn't have any hair yet to shave .hmmmmm usually it takes only maximum 2 days but not this time. hair come up after 4 days. i shave day 5 th.
Since then i used 2 more times and Ti is really sharp. Results was same . now i don't use it went back to my puma gold.
This is makes me think it does gets sharper then it needs to shave (personal preferences)/
hope this helps.

i don't know it will depends a lot blades quality too. some blades never will get too sharp.

Sham was that the razor you had me check the sharpness on at the meet? I have never seen a razor that sharp!!!!!!!!!

Phil i am sorry i don't remember if that was the razor then add twice sharpness to it. seems like it cuts root of the hair. i stop using it.

Originally Posted by pjrage

I agree with you that a razor edge can only get so sharp. That's where I was going with my light saber comment

IMHO, polishing the bevel is what makes the razor sharp in the first place. The second the two sides of the bevel meet, EVERYTHING you do from that point forward could be considered polishing the bevel. They can meet at VERY low grits. I think, though, that you are defining "polishing the bevel" as starting the second that you have made some portion of the edge as sharp as it's going to be (0.5 micron assuming that number is correct).

So, I'll jump on board with that argument then, that around the 4k level I will assume (I have no proof) that you are starting to get into the realm of "some areas of the edge are as sharp as they will get."

So, think about it like this. At the 4k level, you have two sides of the bevel, both with scratches in them, meeting up to form an edge. As far as I can tell, the scratches in these two edges of the bevel cause the two sides to not meet up as evenly where they meet (the edge). Since each side of the bevel is basically varying in width from having scratches, the very edge is varying in width also. The complete edge would look jaggedy in width (on a microscopic level) if viewed straight on. That is to say, the edge may be 0.5 microns (or whatever the sharpest they can be is) at some points, and, say 2 microns at others. Where the two valleys of the scratches meet perfectly, it might be the perfect 0.5 microns in width, but where two peaks of the scratches meet, it is wider, say 2 microns (just making up that number). Does this make sense? I wish I could draw a picture to describe what I'm saying.

Anyway, as you take these scratches out further and further (polish), the edge becomes more and more consistent in width. Just for the sake of argument I'm going to pull some numbers out of the air, assuming that your 0.5 micron width is the sharpest a razor can get. Anyway, let's say that at the 4k level, the edge varies between 0.5 microns and 2 microns in width. Some points where the scratches on both bevel sides meet perfectly are as sharp as possible (0.5 micron), but where the scratches do not meet perfectly, you have varying edge widths as wide as 2 microns. Now, you move on from the 4k to a finer stone. Now you are removing the 4k scratches with 8k ones which aren't as deep. Now the edge varies in width from the same perfect 0.5 micron to, let's say, 1.5 micron at the spots where the scratches "meet up" the worst. Then you move on to say a 12k stone, and now you are varying between, say, 1 micron and 0.5 micron. Then you go to a 16k and get to 0.8 micron and 0.5 micron. Then you get to say, a 30k hone and now you much closer to a consistent 0.5 microns because the scratches are so thin that you really can be very consistent.

Now, these numbers are completely made up to try to illustrate what I'm thinking, but does that make sense?

If you subscsribe to this making sense, then I would argue that as you polish the edge, you are making it a more consistent width that is closer to as sharp as it can possibly get. When the edge is more consistent and also a smaller width, it will cut better. If it cuts better, I define it as sharper. Therefore, polishing makes it sharper.

Or I could be completely wrong, but it makes sense in my head anyway.

This is slightly wrong. The triangular profile where the edge meets will always be a consistant width (if we are assuming it is triangular aka perfect honing, not round tip). However, if you look at it side on, there will be a lateral profile (at the microscopic level) like a very complicated sine wave! JOY!

Now, as I am learning at college, one can explain this with... FOURIER SERIES! If we assume the scratches on one side are regular, with period x, and on the other side, with slightly different period 1.000001x, but out of phase, then the sum will give you a very different sine function, which will be the edge profile. Now, the scratches on a large grit will not be consistant, they will have underlying frequencies and require fourier transforms of there own, (so imagine doing this with something like 4cosx+3sinx+19cos2x+2sin2x+7cos3x...) and as you can imagine, it would be highly implausible that two sine functions that look like that will add up to give you a straight line. However, as the grit becomes smaller, your scratches are smaller (lower amplitude of variation) and more consistant (simpler transforms, fewer underlying frequencies) and so matching the periods will come closer to a straight line (due to simpler transforms) and will have less deviation along the edge (due to lower amplitude). YAY! I bet none of that made sense to anyone, but at least my thousands of dollars spent on education finally turned up a little bit useful...

Originally Posted by jendeindustries

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I totally agree (and actually follow) your thinking here! I had this very epiphany last week (without reading this thread), and posted it on my blog. To take your thought one step further, if you spend too much time on the final stone, you will again end up with an uneven edge because you have established those high and low points on the blade.

How many strokes does it take? We'll have to ask the tootsie pop owl (he'll say 3)

In theory this is right, but would only be true if every stroke were in exactly the same place, which would be statistically implausible (the politically/scientifically correct way of saying impossible). One stroke you may form peaks/valleys along a(x)=ysin(zx), the next stroke would maybe be b(x)=ysin(zx)+.000000001, the next would be c(x)=ysin(zx)+.0000000004, etc. Eventually, if every stroke were very slightly different (which it will be) you will reach an edge equal to the root mean square of the untranslated sine function, which mathematically speaking, is a perfectly straight line equal to Fsum(x)=y*sqrt(2). (Variables: a,b,c, etc are the terms of the fourier series, Fsum(x), which is the overall edge profile. x is the position along the length of the edge, y is the grit of the hone, and z is the fourier transform of a hone's particular profile frequency)
Think of this like electricity. The wall socket is constantly alternating at Fsum(x)=110sin(30x/pi) (60 hertz period, 110V amplitude). This means you are in theory only recieving electricity some of the time. Sometimes you are at peak voltage of 110V, but 60 times every second that number dips negative. Now it would be a bitch to calculate your energy bill if they had to integrate the function of your power consumption. But they don't have too. Because we use so much power, and not just at 2 second increments, they just charge us the root mean square of 110sin(60) times the amount of power we draw. (the point of this analogy was to demonstrate the root mean square idea.) So yes, you could reestablish valleys, but the world is not perfect, so you can't really polish too much, unless you are overhoning.
Also, this begs the question, won't sharpening 500000 laps on a 4k do the same thing? No, because of the high grit, it "gouges" rather than gently scrapes. The last pass will always leave a slightly more distinct profile. This profile on a 30k will be a **** ton smoother than on a 4k.

Honemeisters please correct me as experience trumps explanation, but from what I've read, Glen agrees. It can only get so sharp, but you can polish it to be smooth which translates interestingly enough into literally a comfortable smooth shave.

Originally Posted by gssixgun

Personaly I see sharp as sharp, now harsh -vs-smooth yes I see a difference....

A razor can be sharp and still feel harsh, that sharp and smooth feeling is the sought after condition....and that is what takes a little more work and expeience....

I have always said "Just about anyone can get a razor sharp, it takes talent to get it smooth too"....

This statement is true. The edge cross sectional profile will be consistant, due to consistant material properties in the steel (hopefully) and consistant bevel setting (lets say lynn honed it first). However, as you polish it, you are bringing that edge closer to a straight line ie. smoothing it. So while all edges are sharp, a 4k edge will look like a mountain range under an electron microscope due to pjrage's explanation. So all those peaks will be creating scratches at the cellular level, giving a harsh shave. See? Glen knows his stuff. Sharpness shouldn't change (unless there is a big boo boo), but smoothness can vary a lot based on honing.

I think *think not know* that you could in theory break in a razor on the strop or your face, as the more you use it, the "peaks" will wear away faster than the "valleys" as they are not supported as well by the surrounding steel (less steel is around them as they jut out, while the valleys I would assume are very stable) However I would prefer a gentle smooth edge off the hone that having to break it in forever at my face's cost...

Sham,
I thought it might be since it said Paris on the tang and had stainless scales? I tried it on my arm and the hair just fell over without even feeling it!