by raphar on 10/3/22, 3:31 AM with 129 comments
by briandon on 10/3/22, 4:28 AM
by OGWhales on 10/3/22, 12:51 PM
The site focuses mainly on sharpening razor blades and is full of SEM images of blades in various conditions. Very cool to see.
This page about burrs has some particularly cool images: https://scienceofsharp.com/2015/01/13/what-is-a-burr-part-2/
by dragontamer on 10/3/22, 2:34 PM
I'm no knife expert, but my understanding is that today's best knives use VG-10 steel, which is designed to "chip itself to make itself sharper". So its hard, flexible, slightly more brittle than you'd expect. But these micro-chips end up sharpening the blade more often than not. There's more than one way to design a blade's metallurgy.
For shaving steel, it needs to be as cheap and flexible as possible, so that machines can mass produce them. High end knife-blanks cannot be punched if the steel is too hard or strong (leading to a "price cliff", where the best steels are an order of magnitude more expensive than the punchable lower-cost steels).
--------
So yes, very interesting experiment. But also consider the overall picture: chip-resistance isn't everything.
by Hnrobert42 on 10/3/22, 5:34 AM
I bought a Celestron USB microscope. It was fascinating to look at my skin, nails, desk surface, carpet, anything. Well, at least for the 15 minutes before the device failed. I returned it and never bought a replacement. :-(
Has anyone had luck with a toy-ish microscope in the $200 range?
by userbinator on 10/3/22, 3:51 AM
Considering what started the whole idea of the consumables industry, a patent on making razor blades longer-lasting seems incredibly ironic.
by wrp on 10/3/22, 3:49 AM
What both these studies reveal is an absence of bending of the sharp edge, indicating that the tradition of razor stropping has no real effect.
by AnonC on 10/3/22, 4:42 AM
Extending the life of a razor blade sounds nice, but cutting hair perpendicular to the blade means shaving against the grain, does it not? I don’t want to handle the pain of doing that on the first or second pass while the hair is still long enough (like a couple of millimeters or longer, which cannot be trimmed using a trimmer and needs a blade). But shaving against the grain gives the smoothest skin texture (at the risk of causing ingrown hair, which for me is quite rare).
What I’m saying is that I’d rather the blades dull and need replacement sooner than put up with the burn and pain caused by shaving against the grain from the get go. A few passes with the grain and perpendicular to the grain (sideways) helps the “against the grain pass” be less painful and provide a smoother result.
I’d still love a blade that lasts longer though.
by themodelplumber on 10/3/22, 3:46 AM
That video was oddly pleasant to watch. I admit I was expecting to see the blade become miraculously f'd up in the process, due to the rest of the article, but hair is indeed very soft and the look of that angular cut at such a scale is kind of amazing to think about.
(Perhaps when such microscopes hit Aliexpress we'll see this genre enter the extremely-satisfying-videos arena)
by nehal3m on 10/3/22, 6:44 AM
by dang on 10/3/22, 7:38 AM
Why shaving dulls even the sharpest of razors - https://news.ycombinator.com/item?id=24075855 - Aug 2020 (123 comments)
by silisili on 10/3/22, 4:03 AM
Firstly, I'd read that DE blades actually get sharper after the first shave, due to coating wearing off, then quickly dull after the third or fourth shave. Personally, I'm unsure of this finding, as I always find new blades the best cutting and in fact change my blade every other shave.
Secondly, it's commonplace to the point of common knowledge or folk lore that it is rusting that ruins blades, hence you should soak them in alcohol, or dry them vigorously after each shave. Is this even true?
by asah on 10/3/22, 4:17 AM
by Nomentatus on 10/3/22, 3:54 AM
Skin oils might be a bit of harm, too.
by shric on 10/3/22, 4:04 AM
by slt2021 on 10/3/22, 4:23 AM
if you shave along the direction of hair growth, the blade will approach hair at 15-30 degrees which causes excess wear & tear on a shaving blade.
by wirthjason on 10/3/22, 4:14 AM
Given that the angle of cut matters is it better to shave certain parts of the face with the grain or against?
by hilbert42 on 10/3/22, 10:53 AM
Item 2. In a somewhat oblique vein, during COVID I always wore N95/P2 masks in public and I always took extra heed to follow the instructions that came with them which read to the effect that 'this mask will be less effective on those with bearded faces'.
Clearly that stands to reason so the question is by how much.
I'm constantly bemused by the large percentage masks on bearded faces and whose wearers seem oblivious to the fact that their beards are likely rendering their masks ineffective. Especially so when I see doctors on TV who've beards and who are there specifically to proselytize the virtues of wearing masks. With their beards popping out from behind their ill-fitting masks, it seems strange to me that these highly trained medicos seem oblivious to the obvious fact that their beards are putting them at risk—not to mention that they are setting a bad example.
Now the issue is this: given that a clean-shaven, stubble-free face provides a better mask-to-skin seal than one with stubble, the questions are:
Does anyone know of whether tests have been done on N95-type masks to test the effectiveness of their mask-to-skin seals? If so, whether any significant leakage was detected at the seal and whether stubble growth throughout the day worsened said leakage (the implication being that by the afternoon/evening masks would be less effective though increasing seal leakage)?
The corollary of the question would be to ask if a beard stubble impedes the effectiveness of the mask-to-skin seal then at what point in the growth of a newly-forming beard (at what stubble length, etc.) does the stubble render the mask ineffective (dangerous to wear)?
by ripe on 10/3/22, 1:27 PM
Am I the only one who finds the repeated incorrect spelling of "heterogeneous" annoying?
The worst part is, the way they spell it, "heterogenous", actually means something else. Just not what they think it means...
by denton-scratch on 10/3/22, 10:53 AM
It seems that microscopically, the honed edge of the blade looks like a comb of teeth. When you shave, these teeth fold over. Stropping apparently straightens out the folded edge.
Eventually these teeth break off, and the edge has to be remade. That can be done with a few strokes on a coticule, every 6 months or so.
The authors apparently experimented on stainless steel blades; stright razors are made from carbon steel, which doubtless has a different microcrystalline structure.
[I know, the article's about disposable razors]
by helsinkiandrew on 10/3/22, 4:29 AM
by aidenn0 on 10/3/22, 3:56 PM
by agentultra on 10/3/22, 1:05 PM
Yet one must still sharpen the edge eventually.
by namlem on 10/4/22, 2:36 PM
by ChrisArchitect on 10/3/22, 6:17 PM
by hoseja on 10/3/22, 8:14 AM
by bentobean on 10/4/22, 3:55 AM
This team is playing with fire and should tread carefully. If they should happen to stumble across the secret to a “perma-sharp” razor blade that never needs replacing, I have no doubt that “big razor” will dispatch them with a vengeance.
The team lead will be strolling through the park on a lazy Sunday afternoon, when a stunningly beautiful female jogger “accidentally” steps on his foot. He’ll think nothing of it, but what he won’t realize is that he was just on the receiving end of a Polonium 238 injection delivered at the order of the Gillette family.
by Razengan on 10/3/22, 9:02 AM
Growth, removal, color…
You’d think the richest people would want to invest in that research as they grow older.
by xchip on 10/3/22, 10:34 AM
"They found that the simulations predicted failure under three conditions: when the blade approached the hair at an angle, when the blade’s steel was heterogenous in composition, and when the edge of a hair strand met the blade at a weak point in its heterogenous structure."
"Tasan says these conditions illustrate a mechanism known as stress intensification, in which the effect of a stress applied to a material is intensified if the material’s structure has microcracks. Once an initial microcrack forms, the material’s heterogeneous structure enabled these cracks to easily grow to chips."
by yuan43 on 10/3/22, 2:48 PM
by currenciessfe on 10/3/22, 8:04 AM
So why are there no ceramic blade razors?
by 1vuio0pswjnm7 on 10/3/22, 7:57 AM
by c7b on 10/3/22, 12:58 PM
by SubiculumCode on 10/3/22, 3:14 PM