Is there actually an accurate way of gauging a razor's sharpness?

Mastropiero

Mastropiero

Gone but not forgotten...
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Jun 16, 2021
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I would say there's only one, and that is, shaving with it. Even then, it will depend on the feeling/result ratio.

What do I mean by this? Well, this morning I honed a Robert Kelly "Kelson" razor, English, pre 1892. I was quite happy with the way it was behaving on the stones, and it did shave the hairs on my arm pretty effortlessly. It didn't treetop, however, which is something that didn't leave me all that happy. After stropping, HHT was nowhere to be found, it wouldn't cut a hair for its life.

However, knowing that something HHT means nothing, I gave it a go. WTG, there was a bit of pulling (the "feeling" part in the ratio I was talking about earlier), but nothing unbearable, just that "hmmm-I've-seen-better" feeling. Finish, rinse, check, fairly good WTG, promising. ATG, no problems, even fool's pass, despite not being 100% effortless, it was good.

The end result was an absolutely delightful GBS™️, one I could be 98%+ happy.


Granted, someone with a lesser technique, or someone who doesn't know his own face and needs as well as I do, might perhaps struggle a bit more, but I ultimately don't think there's a standard for sharpness. I know people who swear by the HHT, and that would have not even dared to put this razor against their whiskers, just because of it. However, it worked flawlessly for me. Go figure.
 
Somewhere there's a site that evaluates DE blade sharpness by measuring the weight on the blade required to cut a given fibre (presumably something consistent like a fly-fishing trace).

Here you go.

I'm sure something like this could be adapted for use with straight razors. Of course, that by itself won't tell you anything about the quality of the edge, but I'm sure you can work that out for yourself... :)
 
Mastropiero said:
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Stay away from Science, it's very dangerous.
 
I've had the same experience. Treetopping, for me, is the best heuristic about whether or not a blade is ready to leave the stones. That's it. It doesn't tell me whether it will be a good shave, nor a comfortable one. In many cases, it can be both, but not always.

When what you describe happens to me, I take the edge back to the finisher and will often find the next shave will be all of the above: comfortable, efficient, and satisfying.

If I obsessively took photographs of the edges with a USB microscope, I suspect I'd discover some correlation between some small imperfection and the slightly less than perfect feeling edges, but I'm not fussed enough.... :p
 
Oh, I can't be arsed to take pics of my edges. I don't really care enough to bother.

I also tend to assume there's razors that are simply not that good. It happens, no matter how much effort or talent you put into honing them, they just aren't that good. Fortunately, I have honed a sufficient number of razors to my absolute liking, to know that my system works, so if a razor doesn't feel all that great, usually it's the razor. I say "usually" because, despite of my confidence in my abilities, sometimes you have a bad day at the office and you can't hone for shit.
 
@Mastropiero I suspect we have similar preferences in our edge. I prefer a nice smooth edge that is just tree topping and not tugging WTG/XTG. Historically I have never bothered with ATG because I dont with a DE so why start with a straight. This has changed lately because I have been practicing the 14 stroke shave pattern, which includes some ATG on the neck and lower lip, and I am finding it very efficient and starting to understand the appeal of a fools pass. Also noticing as my honing improves and repertoire/tools build I am getting a sharper edge that I am not too pleased with and would prefer a return to the smooth, just tree lopping edge. Still a work in progress and happy I can finally achieve an edge similar to that received from honemeisters. Will now have to go back to previous finishing methods to try and smooth the edges a bit ie: just a coti, JNAT or thuringian edge. This is why the CRoX pasted adjustable loom strop works for me because I am not trying to achieve a laser sharp fools pass edge. Just a smooth ATG/WTG edge is enough. I have never attempted HHT test because tree lopping has been sharp enough. Quite often I am not tree lopping off the stones but am after stropping. Maybe if I can get to tree lopping of the coti before stropping it will be both sharp and smooth :)
 
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For me, an edge must be both sharp and comfortable to shave with. My thinking is that sharpness covers whisker cutting while comfort is how well the edge glides over your skin.

There is only one test that is satisfactory for me and that is the shave test. Cutting hair, like HHT or TTT, can give comparative results but not necessarily give an indication of how well a blade shaves.
 
Gargravarr said:
If I'm doing tree lopping, I usually use a Husqvarna 395XP with a 36" bar and full-chisel skip chain:

h110-0035.webp

... or for anything smaller, I like the 556 with a 20" bar and the same chain:

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Use the right tool for the job. Just trying to be helpful... ;)
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Apologies @Gargravarr I just couldnt help myself

 
Gargravarr said:
Somewhere there's a site that evaluates DE blade sharpness by measuring the weight on the blade required to cut a given fibre (presumably something consistent like a fly-fishing trace).

Here you go.

I'm sure something like this could be adapted for use with straight razors. Of course, that by itself won't tell you anything about the quality of the edge, but I'm sure you can work that out for yourself... :)
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The Bess tester only indicates sharpness cutting a filament thread, as a HHT can cut hair.
however, these do not always translate to shave smoothness,
as a straight sharp knife will cut fresh bread better than a serrated blade, and I know which I prefer to shave with and is not serrated
 
Substance said:
The Bess tester only indicates sharpness cutting a filament thread, as a HHT can cut hair.
however, these do not always translate to shave smoothness,
as a straight sharp knife will cut fresh bread better than a serrated blade, and I know which I prefer to shave with and is not serrated
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Hmmmm, a serrated edged straight razor is something that I haven't tried.
 
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