TE
TechEcho
Home24h TopNewestBestAskShowJobs
GitHubTwitter
Home

TechEcho

A tech news platform built with Next.js, providing global tech news and discussions.

GitHubTwitter

Home

HomeNewestBestAskShowJobs

Resources

HackerNews APIOriginal HackerNewsNext.js

© 2025 TechEcho. All rights reserved.

Why shaving dulls even the sharpest of razors

136 pointsby WalterSobchakalmost 5 years ago

26 comments

nordsieckalmost 5 years ago
1. I&#x27;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.<p>The classic solution to this problem is to grind the secondary bevel more obtusely so that there is more material to &quot;support&quot; 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.<p>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):<p>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.
评论 #24078567 未加载
评论 #24078760 未加载
评论 #24078685 未加载
评论 #24079030 未加载
opwieurposiualmost 5 years 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&#x2F;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<i></i>* off so I always put on shorts before shaving.
评论 #24078285 未加载
评论 #24080161 未加载
评论 #24079023 未加载
评论 #24078301 未加载
评论 #24078307 未加载
评论 #24078489 未加载
ajucalmost 5 years ago
Not &quot;even the sharpest&quot; but &quot;especially the sharpest&quot;. The sharper the edge the easier it is damaged.<p>Also - I&#x27;ve got a cheap beard trimming machine I bought 10 years ago. I use it every week or two, and I haven&#x27;t replaced the blades even once (I don&#x27;t think it&#x27;s even replacable) - still works fine.<p>It seems the solution is to use blades that are almost dull?
评论 #24079345 未加载
jl2718almost 5 years 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.
anitilalmost 5 years 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.<p>I always find myself falling for this sort of &#x27;Well of course the answer is &lt;simplified answer that is wrong&gt;&#x27;<p>Edit: I&#x27;ve posted to &#x2F;r&#x2F;ImageStabilization&#x2F; for that first image - <a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;ImageStabilization&#x2F;comments&#x2F;i54p9s&#x2F;could_someone_help_to_stabilize_this_gif_of_hair&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;ImageStabilization&#x2F;comments&#x2F;i54p9s&#x2F;...</a>
评论 #24077394 未加载
yumrajalmost 5 years ago
&gt; “We’ve learned how to make better blades, and now we want to do it.”<p>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.
评论 #24077304 未加载
评论 #24077495 未加载
评论 #24077531 未加载
peterwwillisalmost 5 years 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&#x27;t cut you, and get very close, without needing any foam. They really are the pinnacle of shaving technology. It&#x27;s amazing how people ignore them for older tech which can only match them with a lot of extra work.
评论 #24079074 未加载
评论 #24078695 未加载
评论 #24080851 未加载
growlistalmost 5 years ago
Wow, amazing imagery. Personally I switched to straight razors recently and given the very low cost of blades I&#x27;m quite happy to use a new one every couple of shaves, which for me is only once a week.<p>Edit: sorry, I meant safety razor, not straight.
评论 #24080892 未加载
ghaffalmost 5 years 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.
评论 #24078361 未加载
taericalmost 5 years ago
And yet I&#x27;ve been on the same razor for well over a year. Can&#x27;t help but think I&#x27;m doing something terrible wrong. :(
评论 #24077983 未加载
评论 #24078234 未加载
评论 #24082277 未加载
1vuio0pswjnm7almost 5 years ago
&quot;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.&quot;<p>So the question is, in shaving, how do we ensure that all hairs are perpendicular to the blade edge and not free to bend?<p>I use Feather blades exclusively; the number of shaves I can get from one blade varies according to the shaving soap used.
评论 #24078619 未加载
m3kw9almost 5 years ago
The videos in there are oddly satisfying.
tcpekinalmost 5 years ago
Here is the actual article, with much more analysis:<p><a href="https:&#x2F;&#x2F;science.sciencemag.org&#x2F;content&#x2F;369&#x2F;6504&#x2F;689" rel="nofollow">https:&#x2F;&#x2F;science.sciencemag.org&#x2F;content&#x2F;369&#x2F;6504&#x2F;689</a>
tyingqalmost 5 years ago
I does ring true that there&#x27;s little financial incentive to create long lasting blades.<p>Even if you produce something that&#x27;s cheaper over a year, I doubt there are many takers for the high up front cost.
dzongaalmost 5 years ago
before gillete started to market multi-use, multi-blade razors. most folks, like me who have course curly hair would&#x27;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&#x27;re done.
评论 #24077549 未加载
caseymarquisalmost 5 years ago
I&#x27;ve heard a second hand story about some titanium razors made internally at &lt;large razor company&gt; which were given out to employees as gifts. They lasted for years, but could never be released as they simply wouldn&#x27;t be able to turn a profit.
评论 #24078110 未加载
评论 #24078210 未加载
ggmalmost 5 years ago
&quot;I liked the scanning tunneling microscope so much.. I bought the company&quot;
hendryalmost 5 years ago
Water dulls blades in my experience.<p>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?
评论 #24085665 未加载
lmilcinalmost 5 years 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.
xmprtalmost 5 years ago
When manufacturers make more money by selling more blades, I don&#x27;t think they&#x27;re going to invest much into this technology anytime soon.
评论 #24077744 未加载
评论 #24077295 未加载
评论 #24077675 未加载
wrycoderalmost 5 years ago
Research probably funded with government grant.<p>They patent it, either start a company or collect royalties. MIT takes a cut. Standard MIT practice.
评论 #24077693 未加载
评论 #24078717 未加载
aidenn0almost 5 years ago
I wonder if powder metallurgy blades last longer considering they tend to make more homogeneous alloys
natmakaalmost 5 years ago
Isn&#x27;t strain-hardening also a factor?
Markoffalmost 5 years ago
Looking at the first photo - aren&#x27;t you supposed to shave against the growth of hair?<p>I use hair clippers, clean shaving is for babies.
评论 #24078868 未加载
knownalmost 5 years ago
Pythagoras theorem in play;
tus88almost 5 years ago
I would like to know this too.