# Why do razors get dull? **URL:** \ **Category:** Factual Questions\ **Created:** [August 29, 2017, 2:05pm UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024 "2017-08-29T14:05:14Z")\ **Posts on this page:** 11\ **Page:** 2
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [August 30, 2017, 6:16am UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/21 "2017-08-30T06:16:04Z")
Sorry it is late. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [August 30, 2017, 7:14am UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/22 "2017-08-30T07:14:26Z")
I once heard that shaving with cold water extends the life of a blade. I never followed that advice until this summer. I started using cold water a couple months ago and it seemed to work. The first cartridge I used it on lasted weeks longer than usual. So long that the lubricating strip had mostly worn off. Any idea why this works? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 30, 2017, 8:53am UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/23 "2017-08-30T08:53:19Z")
> [@Machine\_Elf](#): > > I suspect stones would stay jagged much longer if you removed the sediment from the water. [Plain water at extreme velocities](https://en.wikipedia.org/wiki/Water_jet_cutter) can cut soft materials, but getting through harder materials requires abrasives. Or time and repetition. Sure, sediment in water erodes rocks, but some of the erosion is dissolution or wear from the water itself. A softer material can abrade a harder one - for a simpler example, rubbing a sharp bit of copper on a flat piece of steel will scratch the steel, even though the copper is softer (the copper comes off worse, of course, but so do the beard hairs in the OP) ---
**Author:** ![FoieGrasIsEvil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foiegrasisevil/32/16638_2.png) [@FoieGrasIsEvil](https://boards.straightdope.com/u/FoieGrasIsEvil)\ **Post date:** [August 30, 2017, 11:40am UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/24 "2017-08-30T11:40:52Z")
> [@dtilque](#): > > I once heard that shaving with cold water extends the life of a blade. I never followed that advice until this summer. I started using cold water a couple months ago and it seemed to work. The first cartridge I used it on lasted weeks longer than usual. So long that the lubricating strip had mostly worn off. > > Any idea why this works? Part of this may be due to the fact that you get a better shave with cold water than hot, so your perception may be colored by this. ---
**Author:** ![R.P.McMurphy](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@R.P.McMurphy](https://boards.straightdope.com/u/R.P.McMurphy)\ **Post date:** [August 31, 2017, 12:03am UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/25 "2017-08-31T00:03:59Z")
Not to dispute anything that has previously been posted but I would like to add this: These blades are extremely thin and they are very sharp. That is due to taking a thin piece of steel and honing it to to a thinner edge. I once worked in a lab and had to hone microtome blades. These were used to cut extremely thin cell samples. What we did was examine the edge of the blade under a 500x microscope. The edge of a blade that was “dull” looked like the Himalayas. It would be put on a honer for hours. When it was sufficiently honed the edge looked perfectly straight. Razor blades are thin and extremely sharp when the leave the factory. It is not that difficult to, over time, dull them due to a variety factors that were pointed out earlier. Yes, if you could put them on a honing machine you could restore them. Of course, that is pretty much impractical. So, they sell you new ones. Our microtome blades would “dull” doing work with cells that were hardly as sharp as the steel they were made of. Still, we would have to maintain them. Corrosion, the edge bending, whatever. I hate to think what a “sharp” kitchen knife would look like under a 500x microscope. That’s the physical world. ---
**Author:** ![Weisshund](https://avatars.discourse-cdn.com/v4/letter/w/ba8739/32.png) [@Weisshund](https://boards.straightdope.com/u/Weisshund)\ **Post date:** [August 31, 2017, 12:22am UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/26 "2017-08-31T00:22:10Z")
> [@Ornery\_Bob](#): > > I buy the 12 pack of disposables at the 99 cent store for less than $2 and use each razor for a week and then dispose it. Total cost for the year is like $8. Shaving… meh. Do you have hair on your face? Those dollar store things dont even touch my facial hair unless you count ripping snagging and pulling. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [August 31, 2017, 12:20pm UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/27 "2017-08-31T12:20:42Z")
I get many months of use out of one disposable twin-blade (for trimming around the beard). Sort of like Winston Smith in _1984_. 🙂 ---
**Author:** ![Oredigger77](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/oredigger77/32/3181_2.png) [@Oredigger77](https://boards.straightdope.com/u/Oredigger77)\ **Post date:** [August 31, 2017, 6:32pm UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/28 "2017-08-31T18:32:10Z")
> [@Jackmannii](#): > > I get many months of use out of one disposable twin-blade I’m still using the razor I bought in 2012, of course, I use a straight razor and I’ll probably die using the same blade. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [August 31, 2017, 6:36pm UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/29 "2017-08-31T18:36:16Z")
> [@Oredigger77](#): > > I’m still using the razor I bought in 2012, of course,\*\* I use a straight razor and I’ll probably die using the same blade.\*\* That could be read more than one way. :eek: 😃 ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [August 31, 2017, 6:44pm UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/30 "2017-08-31T18:44:29Z")
> [@running\_coach](#): > > That could be read more than one way. :eek: > > 😃 My thought, too. ---
**Author:** ![Oredigger77](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/oredigger77/32/3181_2.png) [@Oredigger77](https://boards.straightdope.com/u/Oredigger77)\ **Post date:** [August 31, 2017, 7:16pm UTC](https://boards.straightdope.com/t/why-do-razors-get-dull/795024/31 "2017-08-31T19:16:27Z")
> [@running\_coach](#): > > That could be read more than one way. :eek: > > 😃 LOL. I wish that had been intentional [Previous page](https://boards.straightdope.com/t/why-do-razors-get-dull/795024.md?page=1)