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Why shaving dulls even the sharpest of razors
- yumraj 6y 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 6y agoCartridge 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-Razor-Blade-Cartridges-Refills/zgbs/beauty/13271084011 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 6y 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-Rasierklingen/dp/B00DIW3VHG https://www.amazon.de/Shaving-Factory-Derby-Professional-Ras...
- yumraj 6y agoOf 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 6y agoYou 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 6y agoGame theory. If a smaller name starts using those techniques to gain market share then the others will have to as well.
- aaron695 6y agoMen 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.
- anitil 6y agoHuh, 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/could_someone_help_to_stabilize_this_gif_of_hair/ https://www.reddit.com/r/ImageStabilization/comments/i54p9s/...
- aaron695 6y agoI 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-razor-blades/ https://www.bruceonshaving.com/2010/11/17/palm-stropping-raz... [edit] Sorry, as Someone1234 points out I actually meant cartridge razor
- deleted 6y ago[deleted]
- gpsx 6y agoCooks 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 6y agoI suspect cartridge and safety razor blades are too hard (e.g. martensitic or carbide; see https://en.wikipedia.org/wiki/Razor_blade_steel 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.)
- xmprt 6y agoWhen manufacturers make more money by selling more blades, I don't think they're going to invest much into this technology anytime soon.
- badrabbit 6y agoDIY blades would be cool though. I can imagine a small company selling long lived blades for a high price.
- jayd16 6y agoThey'll just start marketing the gel strips more heavily.
- keenmaster 6y agoUnlike 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.
- jl2718 6y agoI 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.
- dzonga 6y agobefore 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 6y agoIf you like single-blade disposable razors, you'll love a safety razor ;)
- FridgeSeal 6y agoI’ve been meaning to buy a decent safety razor setup for a while-any suggestions for brands or models?
- solraph 6y agoNot 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.
- ghaff 6y agoI 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 6y agoYears 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 6y agoI 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-disposable-razors-keep-them-sharp-0158954/#:~:text=Stay%20Sharp%20with%20Pure%20Alcohol,sharp%20and%20free%20of%20rust 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.
- wrycoder 6y agoResearch probably funded with government grant. They patent it, either start a company or collect royalties. MIT takes a cut. Standard MIT practice.
- Qahlel 6y agoThey patent it, sell it to Gilette and we never ever hear of this tech again.
- s1artibartfast 6y agoand everybody benefits.
- wrycoder 6y agoNot 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 6y agoThat 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.
- m3kw9 6y agoThe videos in there are oddly satisfying.
- taeric 6y agoAnd 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 6y agoYes, try a new one you will feel the difference.
- throwaway5752 6y agoSame 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 6y agoYeah, 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 6y agoI 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 6y agoI 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 6y agoFor 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.
- caseymarquis 6y agoI'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 6y 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.
- sliken 6y agoBut hair is so soft compared to titanium, seems possible that the much greater flexibility might make up for the poorer edge retention.
- throwaway5752 6y agoSeems like a thread where people might be interested in https://knifesteelnerds.com/ 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.
- deleted 6y ago[deleted]
- 1vuio0pswjnm7 6y 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 6y agoFeather 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 6y agoWhen 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 6y agoI 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 6y agoYeah, 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 6y agoI 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.
- natmaka 6y agoIsn't strain-hardening also a factor?
- tyingq 6y agoI 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.
- opwieurposiu 6y agoCartridge 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 6y agoI 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.
- vl 6y agoSafety 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 6y 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 6y agoYou 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.
- nordsieck 6y ago1. 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 6y ago"Less sharp, more durable" sounds like it's pretty much all downside if you're in the business of selling razor blades.
- mturmon 6y agoThe 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 http://www.pm-v11.com/Story.aspx
- ComputerGuru 6y agoThanks for the link! The images are on these pages: Impact testing: http://www.pm-v11.com/TestingImpact.aspx http://www.pm-v11.com/TestingImpact.aspx Wear testing: http://www.pm-v11.com/TestingWear.aspx http://www.pm-v11.com/TestingWear.aspx Sharpening: http://www.pm-v11.com/TestingSharpening.aspx http://www.pm-v11.com/TestingSharpening.aspx
- tus88 6y agoI would like to know this too.
- known 6y agoPythagoras theorem in play;
- peterwwillis 6y agoI 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.
- Semaphor 6y 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.
- evanelias 6y agoIf 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.
- growlist 6y agoIdk. 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.
- Markoff 6y agoLooking 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 6y agoI shave with the hair at first, then against it.
- ajuc 6y agoNot "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 6y agoDefinitely 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 6y agoThis 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
- ggm 6y ago"I liked the scanning tunneling microscope so much.. I bought the company"
- hendry 6y agoWater 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 6y 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 6y agoNot just human hair. I use razors to scar bread loves before baking them. Surprisingly, the razors get dull quite quickly after couple dozen loves.
- tcpekin 6y agoHere is the actual article, with much more analysis: https://science.sciencemag.org/content/369/6504/689 https://science.sciencemag.org/content/369/6504/689
- growlist 6y agoWow, 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.
- aidenn0 6y agoI wonder if powder metallurgy blades last longer considering they tend to make more homogeneous alloys