Why shaving dulls even the sharpest of razors

(news.mit.edu)

136 points | by WalterSobchak 1352 days ago

26 comments

  • nordsieck 1352 days ago
    1. I'm not super familiar with razors, but I am pretty familiar with knives. The chipping they describe is typical of a knife that is ground with an angle that is too acute. In knives made of hard material they fail by chipping, whereas in knives with a softer edge (think German kitchen knives) the edge rolls instead.

    The classic solution to this problem is to grind the secondary bevel more obtusely so that there is more material to "support" the edge. This results in a knife that is less sharp, but more durable. That may be a tradeoff that razor manufacturers are not willing to make.

    2. There are already steel making processes that are designed to make more homogenous steel. The most famous one is probably CPM (Crucible Particle Metallurgy):

    Instead of pouring an ingot (where the additives have a chance to settle into a non-homogenous state, they basically pour the steel through something similar to a shot tower - making lots of tiny homogenous micro-ingots that they later fuse together in what is essentially a sintering process. The end result is a much more homogenous ingot. Practical testing shows that steel made in this way is more performant, although it presumably increases the manufacturing cost.

    • zerocrates 1352 days ago
      "Less sharp, more durable" sounds like it's pretty much all downside if you're in the business of selling razor blades.
    • Polylactic_acid 1351 days ago
      >That may be a tradeoff that razor manufacturers are not willing to make.

      Razors are so cheap ($0.10 each) that there is simply no reason to make them worse in order to last longer when virtually everyone would rather they work as well as possible and spend another 10 cents a week.

      • m463 1351 days ago
        Unless you are buying gillette blades. Even at costco you can spend almost $50 on a bunch of refills.

        Unfortunately I seem to have the best shaving experience with gillette blades. I tried Harry's and other brands, but then I tried gillette again and it was markedly better.

        • fileeditview 1351 days ago
          Just buy a good old safety razor. You can then buy some good razor blades for less than 10 cent a piece or buy the probably sharpest blades on the planet: "Feather". They are at slightly less than 30 cent a piece.

          No matter what you can easily afford a 100 blade pack which will last forever, create less trash than modern razor blades and with a bit of pratice the shave will be at least as good.

          Other blades I can recommend: Derby Premium (black). They are at about 5€-8€ for a 100 and of good quality and sharpness.

          • rsj_hn 1351 days ago
            I am very happy with my feather blades: https://www.amazon.com/Feather-Hi-stainless-Double-Blades-Re...

            They are coated in platinum, each blade lasts about a week, and when I bought my 100 pack, it was 25 cents per blade, although now it's up 38 cents on Amazon.

            For the razor, I also use a feather razor, about $160, which is expensive, but one will last a lifetime.

            https://www.amazon.com/Feather-Stainless-Steel-Double-Edge-A...

            YMMV, but the feather razor is extremely safe and easy to use, although you don't have the same level of control as with other razors. It's a good beginner's razor but I've stuck with it. Shaving is dead simple, I never get cuts, and I don't even use any shaving cream, I shave after getting out of the shower and the hairs are already soft.

          • m463 1351 days ago
            You know I have, but I have moles on my face and have to be SUPER careful. With the gillette blades it's always been not only a nice close shave, but I can do it fast.
            • fileeditview 1348 days ago
              Hehe, my father has a rather big mole on his cheek and I remember that from time to time he cut it while shaving.. bloody mess!

              Take care! :)

        • rainbowzootsuit 1351 days ago
          "Stropping" a disposable razor cartridge on a towel or blue jeans after use, i.e.stroking in the reverse of the shaving direction, will extend its life by at least an order of magnitude in my experience.
        • zepearl 1351 days ago
          I stopped using blades ~3 years ago (used to buy Gillette). Bought a Philips 7000 ( https://www.digitec.ch/de/s1/product/philips-series-7000-s75... ) which I use with water & shaving cream (just a little bit, not as much as when using blades) and I have since then 0 irritations and always a perfect shave without any cuts. I replace the set of rotating blades once every ~1.5-2 years (which means that I replaced them once, hehe). I tried previously 2 other brands/models of electric razor but I didn't like the feeling (I don't liketo shave "dry") nor the results, but this one of Philips is in my opinion totally different.
          • specialist 1351 days ago
            Those rotary shavers look sweet, thanks.

            I don't know why, but I nick and bleed very easily.

            My brother (and former roommate) is a cutthroat partisan. He's kinda nutty about tools, precision, etc. Such a great shave. But somehow his face is more durable than mine.

            I've tried every kind of shaving.

            My Braun 5 is the best product purchase I've ever made. In any category. It's not the greatest shave, for my face. But I never bleed, or get a rash.

            I'm on my third Braun. I keep the retired unit for traveling.

            YMMV.

        • rapnie 1351 days ago
          The last Mach3 blades I clipped on sit there for almost 2 years now. Still shaving fine. Are the blades dull? Undoubtedly. Do I notice that? Not at all. The only time I have small cuts on my face is just after I start using a new blade.

          PS. The blades have this psychological marketing trick of the blue indicator bar, where once it is worn away it is supposedly time to get new blades. Just ignore and use as long as it shaves. Your mileage may vary compared to me, but I'm still getting rid of quite heavy-duty stubbles without issue.

          • artificialidiot 1351 days ago
            I think that blue bar is just for lubrication. You can shave just with water if enough of it is there
          • ydnaclementine 1351 days ago
            Should replace for just for hygiene reasons, similar to toothbrush. Lot's of dead skin cells built up on that I'm sure
            • rapnie 1351 days ago
              I don't think there will be much difference between, say, one month of use and times that are longer than that. Of course a good cleaning after use is necessary.
        • cbzbc 1351 days ago
          Skip the flavour of the month and go with their older products - for which the cartridges are far cheaper (especially with frequent deals). I still use the Sensor series cartridges - more blades just makes for more clogging of the cartridges.
          • subhro 1351 days ago
            In the other news, a guy gives up on razor blades and picks up a straight razor. :)
        • noir_lord 1351 days ago
          I just use electric trimmers, it's close enough to pass as a shave for government work with no mess since I use it in the shower.
      • nattmat 1351 days ago
        Where I’m from Gillette is the popular brand, and they are $5 to $7 each.
        • rgoulter 1351 days ago
          There are different types of razors.

          Gillette double-edge safety razor blades are about 0.10 USD each. Gillette cartridge razors are about 6 USD each.

          The former is "expensive razor handle, cheap blades". The latter is "cheap razor handle, expensive blades". The more expensive cartridge razors don't provide a superior shave, but are much much safer to use.

          A safety razor handle costs as much as a pack of cartridge razor blades.

          The keywords to lookup would be "wet shaving" to find out more about the safety razors.

          • canofbars 1351 days ago
            > but are much much safer to use.

            You say that like double edge blades are super unsafe. At worst if you are unskilled you end up with a minor cut which you just stick a band aid over and are perfectly fine.

    • mturmon 1351 days ago
      The CPM process you describe sounds similar to so-called PMV-11 steel, which is used in some high-end chisels and woodworking planes. It’s not just marketing, several professionals who are mostly impartial have said its noticeably better than conventional tool steels.

      There are some nice wear images off the site below as well.

      http://www.pm-v11.com/Story.aspx

      • ComputerGuru 1351 days ago
        Thanks for the link! The images are on these pages:

        Impact testing: http://www.pm-v11.com/TestingImpact.aspx

        Wear testing: http://www.pm-v11.com/TestingWear.aspx

        Sharpening: http://www.pm-v11.com/TestingSharpening.aspx

      • nordsieck 1351 days ago
        Not to derail the conversation, but I spent some time reading about PM-V11. Is there a data sheet somewhere? It looks to me like a mystery steel, which I'm always pretty skeptical of.

        Specifically: while it's very hard to make a particular steel perform better, it's very easy to make a particular steel perform more poorly. I'm not claiming that they purposefully engaged in malfeasance, I'm just generally skeptical.

        I'm particularly skeptical of their claim that it outperforms CPM-M4, which is generally used for bladesports[1] for its ability to take a fine edge and resist mechanical edge deformation. I'm not surprised by the difficulty they had in sharpening it, though.

        ___

        1. https://www.youtube.com/watch?v=YkemT5ciBnw

    • 55555 1351 days ago
      But would they make more or less money if their blades lasted longer?
  • opwieurposiu 1352 days ago
    Cartridge razors are garbage, but they are idiot-proof. I use a straight razor (cuthroat) and hone it a few strokes with 8k diamond after every use, no leather strop. Even with the time spent sharpening it is faster than a cartridge razor because it cuts a wider swath and never clogs. It took me quite a few iterations to find a razor/sharpening tool combo that worked properly. A safety razor works almost as well with no fuss sharpening. The other downside of a straight razor is if you drop it could cut your d* off so I always put on shorts before shaving.
    • catalogia 1352 days ago
      I like the middle-ground; safety razors. They're exceptionally cheap and idiot proof. Mine really doesn't clog like cartridge razors either. Cartridge razors seem like a scam in nearly all respects, although I concede loading them is probably safer for the elderly or generally those with dexterity problems.
      • speakspokespok 1351 days ago
        Switched to a safety razor (Also called a Double Edge) after Mach3s had been out for awhile and they started jacking up the price. That must have been 2005ish and I've not really used anything else since. For quality of shave there is no comparison. Badger & Blade forum had a good process at the time where you started with a certain blade and worked up the sharpness ladder as your skin toughened up and you found the blade/razor combo that worked best for you. I'm a Personna Prep and Merkur 34C guy myself.

        Shaving with a double edge instead of using a disposable is comparable to preparing your own dinner rather than going to McDonald's. It's a skill, it takes time, it's far for economical, there's a ritual to it, and it's enjoyable. It's also a uniquely positive masculine thing (and I think that that does matter) and one day I can pass the razor to my son or grandson.

        > Merkur 5C

      • evanelias 1351 days ago
        Another nice middle-ground is a shavette, which is a disposable blade straight razor, like what barbers use. Although it definitely requires a lot more care/practice than a safety razor initially, you can get a really close shave once you get used to it.

        Shavettes are extremely affordable, like $10 for the base. Unlike a "real" straight razor, shavettes never require sharpening since they just use standard disposable single-edge blades, or a double-edge blade split in half.

      • vl 1352 days ago
        Safety razor requires more time to shave than cartridge razor because it requires more strokes. But I actually prefer it because usually I don’t shave every day. Cartridge razor clogs up in this case. When I shave every day I use either cartridge razor (Dorco) or wet electrical (Braun 9000). Both work greatly for daily shaving, fail for shaving every few days.
        • yumraj 1352 days ago
          > Safety razor requires more time to shave than cartridge razor because it requires more strokes.

          Not sure about that. I generally do 2 passes with both cartridge or safety razor.

          I had started with safety razor, then moved to cartridges for many years, and now am back to safety razor, with a better razor.

          Safety razor probably take a couple of extra minutes since I'm slightly more careful with it than am with cartridges.

        • Polylactic_acid 1351 days ago
          You can get a razor that has 3 blades and uses the standard double edge blades. You just snap them in half inside the wrapping and then load the 1.5 full size razor halves in.
      • Fezzik 1352 days ago
        Also: entirely recyclable.
        • dehrmann 1351 days ago
          Yes, but I can't imagine scrap metal people like dealing with them.
          • Fezzik 1351 days ago
            This is a great way to do it if you don’t have a good local option: https://gillette.com/en-us/about/terracycle.

            I fill up a coffee can with the used blades (it takes years to do so) and have a place I can take them locally.

            Edit, to add: terracycle also takes a lot of other recyclable items that you can seldom-if-ever recycle curbside, like guitar strings. Most big cities have music stores that have partnered with the program and you can drop all musical instrument strings there. Here are all of their programs for those interested: https://www.terracycle.com/en-US/brigades

    • raxxorrax 1351 days ago
      I used a "cutthroat" razor after being sick of others getting dull that quickly. With changeable blades though. They are always in pristine condition and my barber said it is better for most people. 100 pieces à 5$...

      But even with a good brush, which is as essential as a sharp blade for that kind of shaving, it just cannot compete in my opinion. It takes longer and is more bloody. Boy did razors made technological improvements, I think the plastic ones really can compete today.

      It looks easy how barbers do it but it is another thing if you do it in front of a mirror.

    • this_is_not_you 1351 days ago
      I have been using a safety razor for shaving my face for a few years, now I just have a beard and don't shave anymore apart from shaping the beard.

      But I do have to shave my head and I just can't figure out how to use a safety razor or straight razor for that. I keep cutting myself. The margins seems to be quite narrow and boy does your head bleed if you cut it...so I am stuck with cartridge razors which actually works really well. Just means spending more money and dealing with clogging.

      • nelaboras 1351 days ago
        I am using a safety razor for my head. Once every 2-3 shaves I cut myself (usually on my non-handed side) but otherwise no issues. The cut usually heals by the time I'm done and I have rather thin/sensitive skin.

        Derby or Feather blades and a cheap €15 handle. I try to shave once with the grain, once sideways. The blade is held at quite am angle but with very little pressure.

        • this_is_not_you 1348 days ago
          Thanks! Did that work for you from the beginning or was the learning curve bloody?

          I still have many Derby blades and the safety razor from my non-beared times. Might give it another shot.

    • kqr 1352 days ago
      I switched to safety razors because the place where I used to get my straight razor sharpened stopped accepting orders from regular people.

      If someone knows someone in Sweden who will do a good job of making my straight razor... well, razor sharp, I'm all ears.

      • opwieurposiu 1352 days ago
        This is the stone I am currently using, 8k(3 micron) diamond. Made by sprinkling diamond dust on a steel block while electroplating the steel with nickel. The nickel holds the diamonds on pretty firmly so it lasts a long time if you do not abuse it. Cost about $80 https://www.sharpeningsupplies.com/8-Extra-Extra-Fine-Diamon...

        In the past I have used fiber optic polishing film, it works and cost around $1 a sheet. It must be stuck to a very flat surface like a glass table or your bathroom mirror. You want something in the range of 1-10 micron.

        https://www.ebay.com/itm/114106443536

        • emptysongglass 1352 days ago
          I have a Hart steel straight razor and was never able to restore the edge myself using a 4k then 8k wet stone. I always had to send it off to someone in the UK, which made the whole thing untenable; maybe I should try this polishing film?
        • datpiff 1351 days ago
          Very thin (~1mm) diamond stones are now available from China. Dirt cheap.

          https://www.ebay.co.uk/itm/123879373096

      • esaym 1351 days ago
        I think the trick with straight razors is to finish the blade with a denim strop with abrasive compound. I only have two stones, a 2k and a 5k. From there, I strop with a strip of denim that I put a little bit of automotive "swirl remover" (it's like car wax with a bit of abrasive in it, but the point is almost any kind of "polish" compound will work.)

        This blog describes why denim works so well: https://scienceofsharp.com/2016/04/14/simple-straight-razor-...

        • kqr 1351 days ago
          That description makes it sound like it's very easy to make small mistakes that completely ruin the edge. I've just started sharpening my kitchen knives (since a couple of years back) and I'm not confident enough in my honing abilities to risk a razor. Maybe in ten years' time or so!
      • subhro 1351 days ago
        I sharpen my straight razor at home. Get a 3K, 5K, 8K and maybe a 12K naniwa superstone. Unless you massively damage your razor somehow, You would be good for life.
    • stormdennis 1352 days ago
      How many toes, you got?
      • opwieurposiu 1352 days ago
        I got plenty of toes, but only one d*. Toes are expendable.
        • lookdangerous 1351 days ago
          I dropped a kitchen knife on my foot from a dish drying rack yesterday. Granted, it was not my toes, and luckily, it was just a surface wound, but I would probably be wearing shoes while shaving.
  • ajuc 1351 days ago
    Not "even the sharpest" but "especially the sharpest". The sharper the edge the easier it is damaged.

    Also - I've got a cheap beard trimming machine I bought 10 years ago. I use it every week or two, and I haven't replaced the blades even once (I don't think it's even replacable) - still works fine.

    It seems the solution is to use blades that are almost dull?

    • fho 1351 days ago
      Definitely not an expert here but I think the difference is that trimming machines "cut" by pinching the hair between two moving surfaces. That way you can have a 90 degree angle at the cutting edge that is much sturdier than a blade that is designed to cut.
      • JeremyNT 1351 days ago
        This is my understanding as well.

        I've tried every form of razor and - despite all the folklore - the best[0] shaves for me are to be had by electric shavers, which operate on this principal. These have a foil which the hair can protrude past, then it is sheered off by either rotating or oscilating "blades" that push the hair against the foil.

        It's like a pair of scissors, which can operate when "dull" - because there's something to push against, they don't need to be nearly as sharp.

        [0] "best" meaning a combination of least discomfort, time efficiency, and closeness - a safety razor against the grain can get closer, but it's a miserable experience

  • jl2718 1352 days ago
    I assume they mean crystalline domain heterogeneity. The best metals are single-domain so that there are no fissures along the boundaries. But that takes very pure material and very slow cooling. A good alternative is nanacrystalline or amorphous domains, which are fairly simple, just blast with microwave energy during cooling. This can make a very strong metal with great working properties, a bit softer, but doesn’t fracture.
  • anitil 1352 days ago
    Huh, I always thought that it was oxidation from getting wet that damaged the blade. I even remember getting a recommendation to clean the blade with alcohol to dry it of faster.

    I always find myself falling for this sort of 'Well of course the answer is <simplified answer that is wrong>'

    Edit: I've posted to /r/ImageStabilization/ for that first image - https://www.reddit.com/r/ImageStabilization/comments/i54p9s/...

    • aaron695 1352 days ago
      I palm strop my safety razor, the idea is to smooth the microscopic bumps. No idea if it's scientific.

      https://www.bruceonshaving.com/2010/11/17/palm-stropping-raz...

      [edit] Sorry, as Someone1234 points out I actually meant cartridge razor

      • gpsx 1352 days ago
        Cooks use a knife straightener on their knives to keep them sharp longer. Well, I'm not a cook, but I do it too. It works really well. I was wondering if people could do this on razors. I think this is equivalent to palm stropping. For a cartridge, I think something with small metal teeth, at the right angle, ran back and forth over the blades, would do a good job of straightening the edges.
        • wahern 1352 days ago
          I suspect cartridge and safety razor blades are too hard (e.g. martensitic or carbide; see https://en.wikipedia.org/wiki/Razor_blade_steel) and too sharp for stropping. That's probably why they're more prone to chip rather than deform. A good straight razor is made from a softer carbon steel that, while harder than most stainless steels, isn't quite so brittle. And the edge isn't as 'razor sharp' as safety and cartridge blades, but more rounded.

          I shave with a straight razor, but I'm lazy and use a Feather with disposable blades. Before that I used aluminum hair shaper blades, like what the barber uses on the back of your neck (very sharp and thin, but an aluminum alloy). Such blades are far sharper than a real straight razor and cause razor burn more easily. I always sort of suspected as much. I tried using a traditional straight razor several times, but I couldn't get used to it. The feel is just too different. Several years ago I popped into a barbershop where the owner did a lot of traditional straight razor work (very rare these days), and he confirmed everything--a traditional straight razor has a softer, rounder edge--and disposable blades, like my Feather blades, are far too sharp in his opinion.

          For similar reasons, thinner, harder blades are more likely to nick you because the microscopic chips tear into your skin more easily. By contrast, as a traditional straight razor gets dull it stops working as well but doesn't become more dangerous.

          Same thing applies to chef knives. You can use a "steel" on Western knives because the metal is traditionally softer and has a blunter profile and edge. (If it's a cheap stainless pressed steel, not uncommon in typical commercial kitchens--neighborhood joint, not Michelin--you can literally feel the edge rolled over on a dull knife, which steeling rolls back.) A traditional Japanese knife is more like a straight razor blade--harder steel, thinner profile, sharper edge which you maintain with a strop and waterstone--but still softer and blunter than manufactured razor blades. A cleaver, Western or Asian, is supposed to be very hard (often a cheap but very high carbon steel) but also very blunt. You can't steel or strop it; when it gets too dull you have to grind it or, if you have time to kill, resharpen with a stone. (Confirmed with a Chinese butcher years ago.)

          • KozmoNau7 1351 days ago
            A steel doesn't roll back a folded over edge, it removes material and sets a micro-bevel. It's similar to stropping, but with a hard metal tool rather than a soft leather/denim fabric impregnated with paste. And it's easier to mess up and dull your knife instead, a knife in reasonable condition really shouldn't need more than a couple of light strokes on the steel on either side. Conversely it's almost impossible to over-strop a knife as long as you don't completely mess up the angle and use too much pressure.

            In short, everything you do to work on a knife edge removes material. The difference is in how aggressively it does it, and to which angle.

            If the edge on your knife keeps rolling over or creating a burr just from using it, you're sharpening it to an angle too acute for the steel to properly support.

            In my experience, by far the most important tool is the strop. I can get dull knives shaving sharp with a 240-grit stone and a strop in a couple of minutes, though usually I take my knives to 3000, because it's easier on the strop.

            • wahern 1351 days ago
              Stropping definitely doesn't remove material. It heats the edge which aids in deforming it back into a more preferable shape as you press into the material (leather, canvas). If material was removed it'd embed in the strop and damage your edge, either by chipping or just uneven action.

              A strop with paste is a different beast, IMO. You didn't traditionally use a paste with stropping. I'd bet the rise of pastes, which seem kind of gimmicky, is related to a loss of traditional expertise and knowledge about the function of the strop. Relatedly, because of the rise of safety and cartridge razors, people are accustomed to extremely sharp edges. A traditional straight razor shave feels harsher--more pressure and pulling--than people expect. Utterly unrealistic depictions on TV and film don't help, either. For years I thought I just really sucked at sharpening and honing my traditional straight razors (one of which is a very expensive Thiers Issard given as a gift), but after several traditional straight razor shaves at barbershops, which were consistently harsher than the hairshaper and Feather I normally use, and the discussion with that one barber who was an expert on straight razors, I realized it wasn't my poor blade sharpening skills--well, not just my poor skills. Traditional straight razors just were never meant to be as sharp as manufactured, disposable blades, and can't be unless you want to spend more time maintaining the blade than actually using it. Similarly, if you're constantly removing material the blade won't last very long as it depletes beyond a useful profile. Contrast that with wood planes and chisels, which tend to have very deep, thick profiles because of the need for more frequent sharpening and material removal; you need that depth so the angle of attack diminishes less as it shortens, otherwise you'd need to compensate with a more fragile bevel, which would just accelerate the process.

              Steeling might remove some material, especially when used on harder steels, but in the particular case of pressed stainless I don't think so. (But would be happy to see evidence to the contrary.) Traditional stainless steels (not new alloys with, e.g., molybdenum) are relatively soft. It's part of the reason why they're considered more resilient than traditional steels. They tend to have higher shear and tensile strength than non-hardened steels; they'll deform more before they break so they absorb energy better. So, for example, a stainless steel screw is closer to the resiliency of nails in terms of sheer strength than regular screws. Moreover, a pressed knife almost by definition needs to be made of relatively soft metal. One of my first jobs was working in a kitchen where we used horribly cheap pressed stainless knives for preparing chicken strips. After slicing a bag of chicken breasts you could actually feel the edge rolled over, like a letter J. (EDIT: rolled over is a poor description; if it were completely rolled over deformation by steeling would never work given the direction of the stroke. Note that the letter J isn't upturned on my font.) We'd always have to steel the knifes at least once or twice a shift. If steeling removed that material you'd have metal burrs everywhere, including in your food.

              Maybe steeling traditional Western chef knives does remove material. But if so I wouldn't be surprised if the benefit is in tearing the edge, effectively making a micro-serrated edge that works better than an otherwise dulled edge. Still, I'm dubious that's the primary function if it is at all. Everything I've read and experienced (as a home cook, at least) is that Western knifes traditionally use softer steel, and steeling is for deformation/reformation of the edge without removing material.[1] Steeling a traditional Japanese knife, or especially a straight razor, is verboten because of the potential for chipping, macro or micro. I'd never shave with a straight razor that had been steeled, though I confess I've never tried that specifically.

              That said, I admit the purpose and mechanical action of steeling is debated. I see conflicting discussions (not formal material) all the time, including from professional chefs, and I try not to discount people's experiences. Plus, it's not uncommon for the reality of something to differ than the theory even when the same result (e.g. easier cutting) is obtained. And times have changed. Modern alloys have different properties than traditional steels, so it's entirely possible the steeling action is different on many newer knifes than older ones.

              [1] Indeed, IIUC, the very conclusion of the research article suggests that if steeling worked by cutting material rather than deformation, you'd end up with significant microchipping and by definition a less sharp and uniform edge.

              • KozmoNau7 1350 days ago
                Abrasion absolutely happens when stropping, however it is very mild compared to other sharpening/honing processes.

                This is by far the best resource I've found for explaining sharpening and the concepts of sharpness vs. keenness: https://scienceofsharp.com/

                I don't go nearly to that level of effort in sharpening, as I only sharpen pocket knives, kitchen knives and various tools, I don't bother with straight razors (or any razors at all, but that's a different matter).

          • aaron695 1352 days ago
            Electronic microscope of a Gillette Fusion blade pre and post stropping

            https://nanofabrication.tumblr.com/post/145006851641/ever-wo...

            No idea if it means they are sharper or last longer though.

            • wahern 1352 days ago
              It doesn't look like it's doing anything except removing skin detritus, which is what I'd expect. Interesting pics, though.
  • yumraj 1352 days ago
    > “We’ve learned how to make better blades, and now we want to do it.”

    Unfortunately this is at odds with the interests of blade manufacturers, so I doubt we’ll see better blades anytime soon - at least from the current manufacturers.

    • rgoulter 1352 days ago
      Cartridge razors would surely make more money than safety razors, but people are still able to buy the latter.

      As far as I understand the variety of safety razor blades, there's not a race to the bottom where the more-expensive blades don't sell.

      Insofar as shaving can be a luxury activity, I think it's possible there's room for more higher price for more durable blades for safety razors.

      e.g. The bestsellers here https://www.amazon.com/Best-Sellers-Beauty-Mens-Replacement-... lists a pack of 8 refills for cartridge razors for 24 USD. Searching for "safety razor blades" shows a pack of 100 for 7 USD - 11 USD, and I see a 50 pack for 15 USD.

      • Semaphor 1352 days ago
        > Searching for "safety razor blades" shows a pack of 100 for 7 USD - 11 USD, and I see a 50 pack for 15 USD

        I once got the Derby blades [0], $5.59 for 100. I still have around 90 of them left somewhere in the attic because I got what I paid for. Now, I use Feather blades, about the same price for only 10, but one blade lasts me multiple month and I get better results. But as you said, with safety razor blades you only pay a fraction compared to cartridges anyway ;)

        [0]: https://www.amazon.de/Shaving-Factory-Derby-Professional-Ras...

        • yumraj 1351 days ago
          Of the cheaper blades, I really like Astra. For a nicer blade, I prefer Polsilver over Feather, unfortunately I have had to buy Polsilver from Bulgaria based sellers via eBay.

          Interestingly, the difference between Astra and Polsilver is not much to warrant the price difference. So, when I'm done with my 100+ Astra and 100+ Polsilver, I'll probably just get more Astra. :)

          I pair those with Arko and my shaves have never been better.

        • fileeditview 1351 days ago
          You probably have no need since you use Feathers but I can recommend the Derby Premium (black). It's funny because they are around the same price as the green ones but way sharper.
    • delecti 1352 days ago
      Game theory. If a smaller name starts using those techniques to gain market share then the others will have to as well.
    • aaron695 1352 days ago
      Men hate shopping, men love tech, male shaving blades are really light so could be posted from one location to the world.

      If this works well it would take off for the male shaving market alone, could we skip big corps are evil this time?

      Even if it's a 10% improvement, it's not the Neuromancer future we were promised but someone will license it and raise prices by 10% just for the novelty.

  • peterwwillis 1352 days ago
    I have used straight razors, safety razors, electric razors, and various cartridges. A good multi-blade cartridge is vastly superior to anything the layman can do with the first three. They shave all kinds of growth in one pass, don't cut you, and get very close, without needing any foam. They really are the pinnacle of shaving technology. It's amazing how people ignore them for older tech which can only match them with a lot of extra work.
    • evanelias 1351 days ago
      If you have especially curly facial hair, multi-blade razors have a tendency to yank out some hairs instead of cutting them, especially in places where some hairs grow in a different direction. This in turn causes irritation, razor bumps, ingrown hairs, etc.

      After using multi-blade cartridges my entire adult life, I switched to a shavette (disposable blade straight razor) a few months ago and it pretty much immediately solved all of the skin irritation issues. Plus it's massively less expensive. The downsides are it's slower and more injury-prone, admittedly.

    • Semaphor 1351 days ago
      > It's amazing how people ignore them for older tech which can only match them with a lot of extra work.

      a) Price. You save a huge amount of money over time.

      b) Ritual. I really enjoy whipping up the soap with my brush, and lathering up my face before shaving with my safety razor.

      c) Efficiency. If you don’t shave every day (I sometimes don’t for up to a week), cartridges get clogged way too quickly with thicker hair while my safety razor can easily handle it.

    • growlist 1351 days ago
      Idk. I switched to a safety razor and everything is better now, save for slightly worse nicks, but a shaving block takes care of that. And the cost of a cartridge (couple of quid each?) certainly is NOT better than the cost of a fresh blade in a straight razor (25p or so).

      Edit: old style i.e. safety razor, soap and brush is also far more environmentally friendly than new style i.e. cartridges plus foam out of a can.

  • growlist 1351 days ago
    Wow, amazing imagery. Personally I switched to straight razors recently and given the very low cost of blades I'm quite happy to use a new one every couple of shaves, which for me is only once a week.

    Edit: sorry, I meant safety razor, not straight.

    • Solstinox 1351 days ago
      You mean double-edge, right? I thought straight edge was basically a shaving knife you can sharpen...
      • growlist 1351 days ago
        thanks, edited my comment
  • ghaff 1352 days ago
    I had always assumed based on what I’d heard that corrosion was the main factor in blades wearing out. Which may still be the case. But this suggests that there are still ways that soft materials can still chip very thin cutting surfaces.
    • unclebucknasty 1352 days ago
      Years ago there was some product, essentially a goo, that claimed to dramatically extend the life of blades. The rationale was that hair was too soft to dull a blade, and what was really dulling them was oxidation.

      Don't know what became of the product, but would be interesting to know if corrosion plays a role in the chipping.

      • ghaff 1351 days ago
        I vaguely remember way back when I was a Masters engineering grad student, one of the undergrads had a senior project that involved dipping razors in alcohol and it significantly increased their lifespan because of reduced corrosion. And that does seem to be a thing according to the Internet: https://macgyverisms.wonderhowto.com/how-to/extend-life-your....

        Doesn't mean you can't still chip thin edges of a (presumably) fairly brittler steel blade with something relatively soft of course.

  • taeric 1352 days ago
    And yet I've been on the same razor for well over a year. Can't help but think I'm doing something terrible wrong. :(
    • rtx 1352 days ago
      Yes, try a new one you will feel the difference.
    • throwaway5752 1352 days ago
      Same here. I use them dozens/hundreds of times. Maybe our facial hair is softer or we aren't discriminating enough! I notice the difference with a new blade, but it doesn't bother me.
      • travisjungroth 1352 days ago
        Yeah, it comes down to hair and skin. I have coarse hair and soft skin. I wear out razors quickly and it becomes very noticeable.
      • ComputerGuru 1351 days ago
        I think it's a structural difference in the hair itself, along the difference between diamonds and carbon. I have facial hair that is prone to fracturing and then giving me splinters that can easily go a few mm deep into my fingers.
        • Infernal 1351 days ago
          I thought I was the only one that got painful beard splinters in my fingers. Can confirm my facial hair is coarse and wiry, individual hairs seem to unravel into many strands like a steel cable.
    • aidenn0 1351 days ago
      For me after about a dozen shaves the razor starts plucking the hairs out rather than cutting them, which both hurts more and leads to ingrown hairs.
  • 1vuio0pswjnm7 1352 days ago
    "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."

    So the question is, in shaving, how do we ensure that all hairs are perpendicular to the blade edge and not free to bend?

    I use Feather blades exclusively; the number of shaves I can get from one blade varies according to the shaving soap used.

    • Semaphor 1352 days ago
      Feather blades are great, but for anyone reading this who thinks about switching to a safety razor from cartridges or electrical ones: Don’t start out with them, they are really unforgiving even for safety razor standards in how easy it is to cut yourself.
      • wolfgang42 1351 days ago
        When I switched to a safety razor I bought a sampler pack of different brands of blades. The Feather blades felt great; there was no grabbing or skipping, I’d just glide the razor across and all the hair would be gone. Then I’d look in the mirror and there’d be blood dripping down my neck. They are so sharp that I wouldn’t feel it at all.
      • Polylactic_acid 1351 days ago
        I started with feather blades. Cut myself a bunch the first few times. It doesn't really hurt but its just annoying because you don't want blood on your clothes. Eventually looked up a guide and found out I was doing it wrong and now I basically never have issues.
        • Semaphor 1351 days ago
          Yeah, that’s what I meant. Feather aren’t super hard to use, but they are not beginner-friendly. It’s easier to learn with other blades.
      • 1vuio0pswjnm7 1351 days ago
        I also use a Muhle R41. I have used this since the beginning and never had any problems with cuts. I did have to experiment with a few soaps find the right one to get more mileage out of the blades though.
  • m3kw9 1352 days ago
    The videos in there are oddly satisfying.
  • tcpekin 1351 days ago
    Here is the actual article, with much more analysis:

    https://science.sciencemag.org/content/369/6504/689

  • tyingq 1352 days ago
    I does ring true that there's little financial incentive to create long lasting blades.

    Even if you produce something that's cheaper over a year, I doubt there are many takers for the high up front cost.

  • dzonga 1352 days ago
    before gillete started to market multi-use, multi-blade razors. most folks, like me who have course curly hair would've only used disposable blades only once. n I find, single blade razors to be effective, no razor bumps etc. just wet with water, a light moisturizing oil such as almond n you're done.
    • news_to_me 1352 days ago
      If you like single-blade disposable razors, you'll love a safety razor ;)
      • FridgeSeal 1352 days ago
        I’ve been meaning to buy a decent safety razor setup for a while-any suggestions for brands or models?
        • solraph 1352 days ago
          Not the GP, but I'd recommend Merkur Classic Safety Razor 33C, or any of the Merkur models that are generally discussed as beginner friendly, and an sampler pack of blades.

          The sampler pack is key. Every person is different, and every DE razor user I know uses something different. I won't even tell you what I use, because it's not relevant.

          As a secondary recommendation, shaving brushes and a proper shaving cream / soap are incredibly worthwhile investments. I usually suggest Proraso as a cheaper, but still decent starter soap to use until you have a better idea of what works for you.

  • caseymarquis 1352 days ago
    I've heard a second hand story about some titanium razors made internally at <large razor company> which were given out to employees as gifts. They lasted for years, but could never be released as they simply wouldn't be able to turn a profit.
    • nordsieck 1352 days ago
      > I've heard a second hand story about some titanium razors made internally at <large razor company> which were given out to employees as gifts. They lasted for years, but could never be released as they simply wouldn't be able to turn a profit.

      That seems unlikely to me.

      Properly heat treated steel is considerably harder than titanium. This is why titanium knife blades are generally limited to niche applications (like dive knives, although that market is being contested by modern rust-proof steels like H1).

      Material hardness is one of the leading factors in edge retention.

      • throwaway5752 1352 days ago
        Seems like a thread where people might be interested in https://knifesteelnerds.com/, which has made the front page on HN on a couple of occasions. I have no relationship of any kind, beyond finding it interesting.
      • sliken 1352 days ago
        But hair is so soft compared to titanium, seems possible that the much greater flexibility might make up for the poorer edge retention.
  • ggm 1351 days ago
    "I liked the scanning tunneling microscope so much.. I bought the company"
  • hendry 1351 days ago
    Water dulls blades in my experience.

    You need to ensure they are dried well after use, otherwise they dull far quicker. I have no idea why, so perhaps someone can test my hypothesis?

    • nordsieck 1351 days ago
      > Water dulls blades in my experience.

      I've heard that corrosion can be particularly damaging to the very edge of blades. The idea is basically that all corrosion is generally limited to small surface patches (in the presence of good maintenance) however, the very edge of the blade has a very high surface area to mass ratio, so corrosion affects the edge more than anywhere else.

      I'd expect any razor that is designed to be around water to be of stainless steel or some other corrosion resistant material, but I suppose it's possible that corrosion happens on the edge anyhow (albeit at a much slower rate).

  • lmilcin 1351 days ago
    Not just human hair. I use razors to scar bread loves before baking them. Surprisingly, the razors get dull quite quickly after couple dozen loves.
  • xmprt 1352 days ago
    When manufacturers make more money by selling more blades, I don't think they're going to invest much into this technology anytime soon.
    • keenmaster 1352 days ago
      Unlike with mature tech platforms, successful entry into the market is not exceedingly difficult. A new company can offer everlasting razors. Then cleaning cartridges and other refills will become the new razors.
    • badrabbit 1352 days ago
      DIY blades would be cool though. I can imagine a small company selling long lived blades for a high price.
    • jayd16 1352 days ago
      They'll just start marketing the gel strips more heavily.
  • wrycoder 1352 days ago
    Research probably funded with government grant.

    They patent it, either start a company or collect royalties. MIT takes a cut. Standard MIT practice.

    • Qahlel 1352 days ago
      They patent it, sell it to Gilette and we never ever hear of this tech again.
    • s1artibartfast 1351 days ago
      and everybody benefits.
      • wrycoder 1350 days ago
        Not if you’re a taxpayer that would rather not fund such things.

        In other words, the government grant should at least be refunded from the profits.

        • s1artibartfast 1348 days ago
          That is a reasonable opinion to hold, as long as you understand that direct financial profit not the purpose of nearly all government spending.

          The intended return on investment is the knowledge generated by scientific research, as is maintaining the scientific research pipeline and subsidizing academics. More profit for MIT and corporations is also a positive outcome, as is better razors for US consumers.

          If most voters believe this is a net positive, they can sign the rest up to pay for it in our democratic system.

  • aidenn0 1351 days ago
    I wonder if powder metallurgy blades last longer considering they tend to make more homogeneous alloys
  • natmaka 1352 days ago
    Isn't strain-hardening also a factor?
  • Markoff 1351 days ago
    Looking at the first photo - aren't you supposed to shave against the growth of hair?

    I use hair clippers, clean shaving is for babies.

    • m463 1351 days ago
      I shave with the hair at first, then against it.
  • known 1352 days ago
    Pythagoras theorem in play;
  • tus88 1352 days ago
    I would like to know this too.