> An in-situ hair cutting experiment in a scanning electron microscope, showing the chipping process. Image: Gianluca Roscioli
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)
There are a large number of electron microscope images here showing the results of various sharpening tools including strops with and without added abrasives.
Thanks. Those studies are interesting, although after reading What Does Stropping Do? I feel like I still don't have a clear answer on whether it does any good to strop before shaving. The photo evidence seems really ambiguous.
It straightens and sharpens the edge, which is likely to improve the shaving experience.
It's unconventional, but I use an abrasive when stropping my straight razor (quarter micron diamond paste), which greatly increases the sharpening effect and reduces the need for other sharpening (traditionally, honing on stones).
I don't shave with a straight razor, but I do sharpen carving tools for woodworking.
I strop with a fine honing compound on the strop, and the purpose of that for my application is to get a more highly polished edge than I get off of stones. The[0] explanation among woodworkers being that a more polished edge has fewer micro serrations along the edge that create weak points on the edge for dulling to start. If the edge has fine points from coarser (relatively) stones, they can break off, leaving a definitely non-sharp region behind. Or something like that.
Other tools that are frequently stropped include drawknives. Chisels and plane irons are less commonly stropped because the softer strop inevitably reduces the flatness of the blade at the cutting edge[1].
[0] Ok, one explanation. Some woodworkers will argue bitterly about anything related to sharpening.
[1] The importance of which is another topic that woodworkers will argue endlessly.
The researchers have filed a provisional patent on a process to manipulate steel into a more homogenous form, in order to make longer-lasting, more chip-resistant blades.
Considering what started the whole idea of the consumables industry, a patent on making razor blades longer-lasting seems incredibly ironic.
Just charge more for the longer-lasting blades. Don't forget to make them incompatible with every other product on the market except your own proprietary, overpriced handle.
I imagine there's already a steel capable of this task as well. Razor makers would choose their steel based on cost/performance tradeoffs not because they're already at the bleeding-edge of steelmaking technology.
The patent would keep other companies FROM making longer-lasting razors.
That's the real dark side of patent law - its used by the entrenched businesses FROM competitors entering the market with better technology for up to 17y.
That's exactly how we got Reprap so late - Stratasys patented the whole lot of 3d printing tech, and the patent didnt expire until 2011.
I've read a ton about razors in the past decade or so, and wish more of what has been reported was covered here. This just reports that hairs microchip blades. To what extent does it matter, for example?
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?
Nah, there's no need to alcohol/dry DE blades. They're all made of stainless steel nowadays and don't rust. That advice was maybe from 100 years ago when they were made of carbon steel. You're more likely to dull the blade by accidentally hitting something with its edge (hopefully not your finger) if you take it out of the razor.
As for changing every other shave, I guess it depends on beard and razor. I have a Merkur 34C that tugs like mad whatever blade I use, new, old, in-between, they're all as bad. And an Ikon slant thing that feels like you could use a piece of paper in it and it'd work wonderfully. I go about 60-70 shaves before I can tell the razor might be getting a bit dull in that one.
Feather ASD2. I have extremely thick face hairs, like little wires. Which I find odd, because my head hair and arm hair and such are very fair, thin, soft. It's also a different color...blond vs some copper color(now half gray).
With a new blade, it feels like rubbing a wand on my face. By the 4th shave, it feels like a tiny metal man is plucking each hair from my face. Especially painful in the mustache area.
All cutting edges have in common that the sharper you make them, the more quickly they'll dull. It's why kitchen knives get sharpened at a shallower angle than hunting knives, and those shallower than hatchets and such.
Razors have a much, much tinier edge than even the sharpest filet knife. So basically every cut deforms the edge in someway.
They could potentially make thicker blades, but most people aren't going to ever bother resharpening them, nor would they be able to get the edge correct. And if they make the edge itself thicker... it's going to feel like shaving with an axe.
More acute angles resist abrasive wear better because more material must be removed before the edge radius is too large to cut effectively. More obtuse angles resist deformation and chipping better, but cannot slice through material as effectively.
Interesting article! However I hoped to get some recommendations, or at least “it doesn’t matter what you buy”, and maybe some comments on the performance of multi-blade razors.
Given that the angle of cut matters is it better to shave certain parts of the face with the grain or against?
always against, so that blade approaches hair as close to 90 degrees as possible, cuts quickly and is done.
what really kills the blade and creates cracks is when you cut hair at 15-20 degrees and blade cuts hair and then starts dragging it along your face while cutting and this is how microcracks form and grow in size.
you can create your own experiment with knife and some veggie like green onion. try to cut it at steep angle and drag it along the cutting board - and you will see that it produces much more stress on cutting surface
I prefer to use double edge safety razors and shaving with the grain. It prevents ingrown hairs, but the result is slightly less smooth. It's enough for daily use and very comfortable while shaving. Replacing blades is super cheap so it's always sharp.
This explains why my shaving blade last for me very long time - I always shave in the opposite direction of hair growth, not along, so that blade always approaches hair at nearly 90 degrees.
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.
That does seem to be the most common method. Starting out by going against the grain is just uncomfortable for me. Fine for the second pass though, although I usually go perpendicular to the direction of growth then.
Me too; my hair is coarse. But I'm too chicken to go against the grain with a straight razor. So I keep a Gilette Mach 3 for the second pass. I get a "baby's bottom" result. I wish I had the guts to try against-the-grain with a straight razor. I have tried across-the-grain for the second pass, with disappointing results.
Another tip that has worked for me is stropping the blade by running it backwards on the skin of my arm. It’s anecdote but it certainly seems to give me several more shaves out of the blade. I generally start when I would otherwise throw the blade out.
I do this against a towel after each shave, I saw a video some 10-15 years ago of a guy doing it against jeans. I believe he also verified with a microscope it indeed made the blade sharper.
Neither of the two videos embedded in the linked press release shows any damage to the blade of the razor. They each cut out at the point that the blade has just finished slicing through a hair, while the hair is still in contact with the blade edge and obscuring our view of any hypothetical chips or defects caused by the cutting process. Bizarre.
The first SEM video shows a small-omega shaped scallop in the blade after it cut the hair. It is indeed a shame this is only visible in the final handful of frames before the video loops.
For me though it didn’t detract too much from the awe. What an incredible result.
What I see there is the cut edge of the hair overlapping the blade rather than any change in the blade itself.
The videos are very cool and I appreciate cool videos, but I don't see any evidence in them for the claim of capturing damage to the blades. It's possible that the press release omits clearer videos that unequivocally show damage to the blades during cutting.
Or it's also possible some grad students with a null hypothesis result are hyping their own startup idea - they have a patent on making better steel for such high toughness applications. Surely that's a technology that would have wide impact on a large number of industries, they probably chose razors as a low mass, high value MVP and hope to scale up.
> The researchers have filed a provisional patent on a process to manipulate steel into a more homogenous form, in order to make longer-lasting, more chip-resistant blades.
There are videos in the supplemental to the paper, see https://www.science.org/doi/10.1126/science.aba9490
I love figure S5, it belongs in the surprisingly large family of "physics experiments involving the researcher's own hair" ("cross hairs" on a telescope were originally made from hair or spider silk).
> When he analyzed the SEM images and movies taken during the cutting experiments, he found that chips did not occur when the hair was cut perpendicular to the blade. When the hair was free to bend, however, chips were more likely to occur. These chips most commonly formed in places where the blade edge met the sides of the hair strands.
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.
My problem is I have sensitive skin, and don't feel the cuts at all - which happen much more easily when the blade is slightly dull. Shaving against the grain is a sure fire way to have folliculitis for the next couple of days - as it is I really can't clean shave every day if I want to actually look presentable.
Double Edge shaving solved a similar problem for me. I used to get irritation every time I shaved ATG but that was because I was hitting the wrong side of my face with 5 blades.. Now I can shave easily ATG just by using light pressure and doing WTG first.
I think it's genes that determine the shaving pain threshold.
I can shave with a dull blade, completely dry, against the grain, in any direction, and it doesn't bother me a bit. Occasionally I'll cut myself and not notice.
(I don't use a dull blade since it's not efficient, but I'll use one if nothing else is available.)
If it is gene based, I'm not sure if it's something that moderates pain tolerance, hair / keratin composition, or some combination. I can grow a really thick beard, fwiw.
Switch to double edge razors and you won’t care about the blades again. They only cost a few cent when they aren’t wrapped in a proprietary plastic holder.
Open comb double edge razor lets the blade to reach hair without bending them as much. I'm not sure if it's that or something else, but double edge razors are less irritating than anything else for me.
I don’t have anything useful to say other than damn I love SEM movies!
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?
I picked up a Carson MicroBrite Plus for the same purpose -- looking at clothes/newsprint/etc and it works pretty well. It claims to do 60-120x magnification. No easy way to capture the images but it makes for a good toy.
Would be interested in a recommendation for something with higher magnification
I have a Celestron scope. It has worked fine for all of the years I've had it, though it doesn't give live video out to the PC itself, just to its own internal monitor.
Stropping is not sharpening. Stropping is just bending the edge back into shape when it rolls onto itself. Sharpening involves removing material which is necessary when you have chipping like mentioned in the article.
Stropping is sharpening. A clean strop (without added abrasive) not only straightens the edge, but also burnishes it and removes material by abrasion. Here are some electron microscope images showing the effects.
I've found Astra blades to be good enough for me; quite a step up from the lowest tier (e.g., Bic), but not as fancy as those Japanese blades.
Inflation certainly seems like a good motivator for more people to switch to safety blades — wet shaving should be cheap, and it is if one stops buying the stuff marketed the hardest.
I initially switched years ago because it made more financial sense, but nowadays I just enjoy safety blades more. I don't spend much on blades (10€ for a hundred Voskhod blades lasts me ages), but I do spend a bit on the shaving cream (nothing beats L'Occitane's shaving cream, and it's a local company).
The sharpest blade is not necessarily the best. The "perfect" blade, should such a thing exist, depends on your razor, beard and technique.
Shameless plug: should you start the search for the perfect blade, at https://www.razorbladesclub.com/ you'll find the widest selection of double edge razor blades worldwide.
The razor housing can make a big difference to this as well. I find feathers are far too sharp for me in one of my razors but are excellent in another, while astra blades are perfect in the first one and too dull in the second.
I guess it's mostly just not economical to produce such a thing. As other commenters noted, with good quality disposable safety blades you get between 3 and 10 shaves depending on your hair and preference. When you buy those in a typical bulk package containing 20 cartons of 5 blades each, your yearly expense in terms of blades sits around the €5 point.
Perhaps Gillette could put out one of their fancy twenty-odd blade monstrosities with an extra ceramic blade in front though. I'm sure that's marketable to people who haven't figured out they're spending way too much money on something that costs a fraction if you look beyond the products pharmacies push in your face.
Ceramic knives are so prone to chipping that they effectively have micro-serrated edges even when freshly sharpened. A micro-serrated edge on a razor pulls hairs and cuts skin.
I don't doubt that in your experience ceramic knives cut food better than metal ones, but I suspect you have not used a well-sharpened knife. Mass-produced knives are typically sharpened using belt grinders and do not cut as effectively as knives hand-sharpened by someone skilled at it.
"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."
I read a lengthy article on how the edge of a straight razor reacts to being used.
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.
Item 1. I hate sharpening knives and tools, so I wish someone would do a similar study for wood plane irons/blades (including their different steel types) versus various grinding techniques, grinding grit sizes etc.; and also explain why good old carbon steel often gives a smoother cut than do many of the harder specialized steels that have Rockwell figures which are well into the 60s—even though the fact that carbon steel dulls and blunts much more quickly than do those much harder steels?
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)?
Not sure where you can do it outside the industry, but mask fit tests are required in many (all?) US petrochemical facilities. The test involves an accurate measurement of gases passing through to the mask wearer.
Edit: seems you can just buy a kit https://pksafety.com/3m-ft-20-training-and-fit-testing-kit-i...
Yeah, I'm vaguely aware of this and mask fitting for asbestos removal is almost mandatory in many workplaces.
I suppose, given all the fuss over COVID, I've been rather surprised by casualness over the approach to mask-wearing given that the warning were there on mask packets before the pandemic. I would have thought this would have alerted many to the fact come COVID but seemingly not.
BTW, my attention to detail seems to have paid off so far (I've not caught the disease as yet). Nevertheless, it would have been good to have been able to put some some figures to the practice rather than working anecdotally.
>>I wish someone would do a similar study for wood plane irons/blades (including their different steel types) versus various grinding techniques,
I think you're looking for the book "Knife Deburring: Science behind the lasting razor edge" by Vadim Kralchuk. The author had a good website, but it appears no more and my cursory web search indicates that he has passed away. He has / had a YouTube channel as well.
I'm not bad at sharpening plane irons and when I set my mind to it I can make them razor sharp—certainly sharp enough to shave with but I only test them by shaving the hairs on my arm and they do that very well.
That said, most books on this subject only cover techniques and not the underlying metallurgy. The metallurgy is important but the problem that most of us encounter is that we plane users don't know what it is (as it's usually unspecified).
Even if it is, it doesn't help much. Leaving aside badly-tempered steel (sharpened to red heat on a grinder etc.), some steels are just horrible to work with, I've some block plane blades made in the 1930s that have high tungsten content and they're almost impossible to sharpen well and even when razor sharp they don't cut well and it's never been clear why. Thus my comment about wanting to know more about the subject.
A big part of the aforementioned book is the manner in which differing steels produce a burr, or even micro-burr that can be mistaken for an edge, but cuts poorly and/or deteriorates quickly. A number of deburring techniques are tested on a number of steels and it is noteworthy that there is no single best method - each category of steels responds best to a different manner of deburring. Great longevity was achieved with proper deburring (as shown in the book with a host of SEM photos.
Excellent (aftermarket) plane irons of known alloy are widely available (at least here in the U.S.). I know some woodworkers value having all original parts, but if the primary goal is paper-thin even-width shavings it's hard to beat modern metallurgy.
That's interesting, especially if it has info on ways of identifying steels where micro-burrs really aren't very controllable. One does everything correctly (I even use a lab microscope occasionally) and with some steels micro-burrs sort of flake off irrespective of the method of sharpening and or steeling them.
Some steels are just horrible and tempering and hardness are not necessarily good indicators of quality. I have a few chisels that superficially seem OK and the steel is hard and takes a good edge but five minutes later they're useless, others, sometimes even cheaper ones, turn out to be excellent.
As a techie who like playing with tech toys I thought of using a handheld x-ray fluorescence spectrometers like, say, this one: https://alloytester.com/xrf-steel-tester. There are any number of them around these days but they're expensive even to hire and I can't really justify one just to indulge my curiosity. However though, it would be really nice to go around testing everything that has an edge and logging its alloy properties against actual performance tests. Perhaps some day.
I couldn't care less about original parts (they're tools!)—so long as the tool works well (I don't for a moment consider myself a collector of old tools). That said, when making repairs I'll go to some trouble with old tools to match a tool with its 'correct' parts if possible (but ultimately it's a pragmatic decision—if I don't have the correct part I'll use wherever is to hand or what works best). By that I mean if it's possible to mate together a tool with parts from the same manufacturing source and same era then I'll do. For example, my No. 8 Stanley somehow lost it's lever cap during a move and I had access to several others that would fit but I selected one that came from the same factory and manufactured around the same time (in this instance the plane was of US manufacture/New Britain and made in 1933, so it received another lever cap from the same factory made in the same era (it was of the first generation to use the kidney-shaped slot for the cap's screw). I'm in Australia, so I had lever caps manufactured in the US, UK and here (including UK Record parts) to choose from. Nevertheless, it now has a plane iron of modern manufacture (but I've kept the original one and it's identified as belonging to said plane). There's also another reason to match parts which is that they usually fit better (leaving Bed Rock planes aside, I'm also of the opinion that the best consistent run of 'normal production' planes Stanley ever made came from its US plant and were manufactured between 1933 and about 1941 (the run came to an end when war regulations kiboshed the quality).
I do have a sense of history when it comes to these old hand-tools, my No. 8 is now 89 years old but it's not the oldest, that accolade goes to my No. 45† which dates from 1907. I'm of the opinion that we never actually own these objects, we're just their custodians for life—after all, my No. 8 is still in excellent condition (so are several others which are older), and if looked after with a little care, it'll still have several human lifetimes left in it after I'm gone. BTW, its original owner wrote his name on a piece of paper and dated it then put it in the space under the plane's tote (I'm now very curious to know who he was but I've really no idea). Anyway, that piece of paper stays with the plane (I've really no right to remove it).
Incidentally, I have a copy of Antique & Collectable Stanley Tools - A Guide to Identity & Value - 1996 edition by John Walker. You're likely already aware of it but in case you're not, it's an absolutely invaluable 880-plus page tome on the subject of Stanley tools, there's nothing else its equal. It's the ul...
137 comments
[ 3.2 ms ] story [ 208 ms ] threadThat 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)
That or scanning electron microscopes have gotten a way faster “shutter speed” since I last looked at them.
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.
Indicating that if stropping does help, it's not by the obvious/expected mechanism of bending the sharp edge back.
https://scienceofsharp.com/home/
It's unconventional, but I use an abrasive when stropping my straight razor (quarter micron diamond paste), which greatly increases the sharpening effect and reduces the need for other sharpening (traditionally, honing on stones).
I strop with a fine honing compound on the strop, and the purpose of that for my application is to get a more highly polished edge than I get off of stones. The[0] explanation among woodworkers being that a more polished edge has fewer micro serrations along the edge that create weak points on the edge for dulling to start. If the edge has fine points from coarser (relatively) stones, they can break off, leaving a definitely non-sharp region behind. Or something like that.
Other tools that are frequently stropped include drawknives. Chisels and plane irons are less commonly stropped because the softer strop inevitably reduces the flatness of the blade at the cutting edge[1].
[0] Ok, one explanation. Some woodworkers will argue bitterly about anything related to sharpening.
[1] The importance of which is another topic that woodworkers will argue endlessly.
Considering what started the whole idea of the consumables industry, a patent on making razor blades longer-lasting seems incredibly ironic.
That's the real dark side of patent law - its used by the entrenched businesses FROM competitors entering the market with better technology for up to 17y.
That's exactly how we got Reprap so late - Stratasys patented the whole lot of 3d printing tech, and the patent didnt expire until 2011.
Skin oils might be a bit of harm, too.
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?
As for changing every other shave, I guess it depends on beard and razor. I have a Merkur 34C that tugs like mad whatever blade I use, new, old, in-between, they're all as bad. And an Ikon slant thing that feels like you could use a piece of paper in it and it'd work wonderfully. I go about 60-70 shaves before I can tell the razor might be getting a bit dull in that one.
With a new blade, it feels like rubbing a wand on my face. By the 4th shave, it feels like a tiny metal man is plucking each hair from my face. Especially painful in the mustache area.
Razors have a much, much tinier edge than even the sharpest filet knife. So basically every cut deforms the edge in someway.
They could potentially make thicker blades, but most people aren't going to ever bother resharpening them, nor would they be able to get the edge correct. And if they make the edge itself thicker... it's going to feel like shaving with an axe.
https://knifesteelnerds.com/2018/06/18/maximizing-edge-reten...
Given that the angle of cut matters is it better to shave certain parts of the face with the grain or against?
what really kills the blade and creates cracks is when you cut hair at 15-20 degrees and blade cuts hair and then starts dragging it along your face while cutting and this is how microcracks form and grow in size.
you can create your own experiment with knife and some veggie like green onion. try to cut it at steep angle and drag it along the cutting board - and you will see that it produces much more stress on cutting surface
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.
if blade is not extra sharp, blade starts ripping hair, shaving along the grain in comparison is more forgiving for duller blades.
For me though it didn’t detract too much from the awe. What an incredible result.
The videos are very cool and I appreciate cool videos, but I don't see any evidence in them for the claim of capturing damage to the blades. It's possible that the press release omits clearer videos that unequivocally show damage to the blades during cutting.
s3 is good though. It actually shows some chips.
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.
The two biggest things for me were using a shaving oil rather than a cream, and shaving first with the grain and then across.
The latter required more time as my facial hair is very thick and the “direction” seems to change a lot on my face.
I can shave with a dull blade, completely dry, against the grain, in any direction, and it doesn't bother me a bit. Occasionally I'll cut myself and not notice.
(I don't use a dull blade since it's not efficient, but I'll use one if nothing else is available.)
If it is gene based, I'm not sure if it's something that moderates pain tolerance, hair / keratin composition, or some combination. I can grow a really thick beard, fwiw.
They are $10 for 100-blades, extremely cheap, very sharp, very good at cutting. I highly recommend them.
I only shave twice per razor. Some people shave once-per-razor (throwing away a blade each day). Its just 10-cents a blade after all...
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?
Would be interested in a recommendation for something with higher magnification
https://scienceofsharp.com/2014/08/13/what-does-stropping-do...
https://imustacheyoutoshave.com/sharpening-a-razor-with-your...
I just switched to a double edge safety razor and never looked back.
Why shaving dulls even the sharpest of razors - https://news.ycombinator.com/item?id=24075855 - Aug 2020 (123 comments)
Inflation certainly seems like a good motivator for more people to switch to safety blades — wet shaving should be cheap, and it is if one stops buying the stuff marketed the hardest.
So why are there no ceramic blade razors?
Perhaps Gillette could put out one of their fancy twenty-odd blade monstrosities with an extra ceramic blade in front though. I'm sure that's marketable to people who haven't figured out they're spending way too much money on something that costs a fraction if you look beyond the products pharmacies push in your face.
I don't doubt that in your experience ceramic knives cut food better than metal ones, but I suspect you have not used a well-sharpened knife. Mass-produced knives are typically sharpened using belt grinders and do not cut as effectively as knives hand-sharpened by someone skilled at it.
https://scienceofsharp.com/2018/02/24/ceramic-blades/
Growth, removal, color…
You’d think the richest people would want to invest in that research as they grow older.
We have hair transplants, not really a new thig.
For some woman washing hair is a hours long procedure applying various chemicals :)
Coloring is also "solved" a long time ago.
What do you miss?
"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."
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]
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)?
I suppose, given all the fuss over COVID, I've been rather surprised by casualness over the approach to mask-wearing given that the warning were there on mask packets before the pandemic. I would have thought this would have alerted many to the fact come COVID but seemingly not.
BTW, my attention to detail seems to have paid off so far (I've not caught the disease as yet). Nevertheless, it would have been good to have been able to put some some figures to the practice rather than working anecdotally.
I think you're looking for the book "Knife Deburring: Science behind the lasting razor edge" by Vadim Kralchuk. The author had a good website, but it appears no more and my cursory web search indicates that he has passed away. He has / had a YouTube channel as well.
I'm not bad at sharpening plane irons and when I set my mind to it I can make them razor sharp—certainly sharp enough to shave with but I only test them by shaving the hairs on my arm and they do that very well.
That said, most books on this subject only cover techniques and not the underlying metallurgy. The metallurgy is important but the problem that most of us encounter is that we plane users don't know what it is (as it's usually unspecified).
Even if it is, it doesn't help much. Leaving aside badly-tempered steel (sharpened to red heat on a grinder etc.), some steels are just horrible to work with, I've some block plane blades made in the 1930s that have high tungsten content and they're almost impossible to sharpen well and even when razor sharp they don't cut well and it's never been clear why. Thus my comment about wanting to know more about the subject.
Excellent (aftermarket) plane irons of known alloy are widely available (at least here in the U.S.). I know some woodworkers value having all original parts, but if the primary goal is paper-thin even-width shavings it's hard to beat modern metallurgy.
Some steels are just horrible and tempering and hardness are not necessarily good indicators of quality. I have a few chisels that superficially seem OK and the steel is hard and takes a good edge but five minutes later they're useless, others, sometimes even cheaper ones, turn out to be excellent.
As a techie who like playing with tech toys I thought of using a handheld x-ray fluorescence spectrometers like, say, this one: https://alloytester.com/xrf-steel-tester. There are any number of them around these days but they're expensive even to hire and I can't really justify one just to indulge my curiosity. However though, it would be really nice to go around testing everything that has an edge and logging its alloy properties against actual performance tests. Perhaps some day.
I couldn't care less about original parts (they're tools!)—so long as the tool works well (I don't for a moment consider myself a collector of old tools). That said, when making repairs I'll go to some trouble with old tools to match a tool with its 'correct' parts if possible (but ultimately it's a pragmatic decision—if I don't have the correct part I'll use wherever is to hand or what works best). By that I mean if it's possible to mate together a tool with parts from the same manufacturing source and same era then I'll do. For example, my No. 8 Stanley somehow lost it's lever cap during a move and I had access to several others that would fit but I selected one that came from the same factory and manufactured around the same time (in this instance the plane was of US manufacture/New Britain and made in 1933, so it received another lever cap from the same factory made in the same era (it was of the first generation to use the kidney-shaped slot for the cap's screw). I'm in Australia, so I had lever caps manufactured in the US, UK and here (including UK Record parts) to choose from. Nevertheless, it now has a plane iron of modern manufacture (but I've kept the original one and it's identified as belonging to said plane). There's also another reason to match parts which is that they usually fit better (leaving Bed Rock planes aside, I'm also of the opinion that the best consistent run of 'normal production' planes Stanley ever made came from its US plant and were manufactured between 1933 and about 1941 (the run came to an end when war regulations kiboshed the quality).
I do have a sense of history when it comes to these old hand-tools, my No. 8 is now 89 years old but it's not the oldest, that accolade goes to my No. 45† which dates from 1907. I'm of the opinion that we never actually own these objects, we're just their custodians for life—after all, my No. 8 is still in excellent condition (so are several others which are older), and if looked after with a little care, it'll still have several human lifetimes left in it after I'm gone. BTW, its original owner wrote his name on a piece of paper and dated it then put it in the space under the plane's tote (I'm now very curious to know who he was but I've really no idea). Anyway, that piece of paper stays with the plane (I've really no right to remove it).
Incidentally, I have a copy of Antique & Collectable Stanley Tools - A Guide to Identity & Value - 1996 edition by John Walker. You're likely already aware of it but in case you're not, it's an absolutely invaluable 880-plus page tome on the subject of Stanley tools, there's nothing else its equal. It's the ul...
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/