Why do razor blades wear out?

[alex.shultz]

After reading the fantasting answer to the (almost) age-old question of whether two blades are better than one I got to thinking about razor blades and how they have let me down.

It seems to me that when my razor blade meets my whiskers I should be able to make money betting on the razor blade winning every time. However, after I have used my triple-blade razor for several shaves, I find that in order to get the same close shave I need to either shave "harder", take multiple passes, or switch to a new blade.

I think that these razor sharp blades be able to whack off my whiskers forever without wearing out. It's not like I'm trying to cut through tin cans before slicing a tomato! Can't they make the razor blades with the same "never needs sharpening" edge that those Ginsu knives are supposed to have?

[Marley23]

They don't get really dull, you can still cut yourself real good with them. They just get too worn out to reliably get those tiny hairs, I think. They probably COULD make razors that last longer, but then you wouldn't buy them as much, so I guess they feel nothing is in it for them.

[Desmostylus]

Originally posted by alex.shultz
Can't they make the razor blades with the same "never needs sharpening" edge that those Ginsu knives are supposed to have? Maybe not "never needs sharpening", but there are things a lot harder than steel. Ceramic advanced wet shave razor (http://www.designinsite.dk/htmsider/k0042.htm).The sharp blade is made of yttria stabilised zirconia ceramic.

[Desmostylus]

Might not be all that comfortable to use, though. Kyocera Ceramic Knife F.A.Q.s (http://www.mingspantry.com/kyoccerkniff.html#q21)The peeler is great! How come you don't make a shaver?
Too dangerous! A metal razor blade has a relatively "rounded" edge (under the microscope) which prevents the blade from cutting into the skin. A ceramic razor blade, however, does not have a rounded edge and slices into the skin. Thus, a ceramic shaver would be too dangerous to use. Several engineers in Sendai who tested prototypes can confirm this painful fact!

[Duckster]

I guess being a cut above the rest is not a good thing here.

[Celyn]

'Cos you haven't put them in a pyramid? :)

[Harmonix]

you know, they sell cryogenically treated mach3 blades. They're supposed to last 3x longer.

I've heard good things about them. But i've never tried em. I only need to shave once a week. Yay for being Asian.

Link (http://greatrazors.zoovy.com/product/TM38)

[Barbarian]

Hair is a lot tougher than you think it is-- and the thin edge of your razor blade ends up being pushed out of the way and misaligned. But it doesn't move in a uniform fashion. It gets all folded over itself, on both sides.

With a knife or a straight razor, you can unfold this edge (with the proper use of a steel or a strop). With a double or triple blade razor, you can't do very much. (Well, you can take your thumb and go through a stropping action, but you can only reach one side of the blade.)

I've looked at microscopic shots of razor edges. They are not rounded-- and they do not have microscopic saw-like teeth. The sharper the edge, the closer it gets to a straight line.
Many people disagree with this POV, because there is a historical meme among barbers and chefs that knives actually have microscopic serrations, but they haven't been able to produce evidence to back themselves up.