Why the 2 edges?

[Meles]

Forgive me if this is being posted in the wrong place. Why do Double Edge safety razors have two sides? A total noob question, but I wasn't sure how to search for the answer yet.

I have been switching sides, because... well there were two of them so why not... I was thinking there must be some reason.

 

[zclake]

I think it's so you don't have to rinse it off every two seconds from it getting clogged. If you switch sides about evenly, then you get more use out of the blade as well. This is just my assumption, I'm a noob, so other people would prob know better.

 

[michiganlover]

I don't know the full history, but I think a lot of it was marketing on the part of Gillette.

Ads from that time period emphasized that there were two cutting edges, and 10 cutting edges per box. The idea seemed to be that having two cutting edges meant the blade should last twice as long as a Single Edged blade.

(oddly this doesn't seem to be true, as a typical DE blade lasts just as long as the Single Edge blade used with the competitor to the Gillette razors: Gem; although the Gem blades are thicker, and as such perhaps capable of holding an edge longer.)

 

[gurana]

I think it's also just an efficient use of materials... I'm more surprised that there was never a 4 sided blade invented.

 

[FiXXXer]

If they had four sides, two of the cutting surfaces would be moving horizontally, and be very likely to slice open a nose or an earlobe.

 

[texbilly]

If they had four sides, two of the cutting surfaces would be moving horizontally, and be very likely to slice open a nose or an earlobe.

Unless the razors were designed around the concept...

 

[pauls51]

If they had four sides, two of the cutting surfaces would be moving horizontally, and be very likely to slice open a nose or an earlobe.

You'd need to install the blade very carefully too.. Don't want to slice up your hands before your razor even touches your face

 

[mdunn]

ease of production & marketing

if youre cutting one side of the blade in the factory, why not cut two. Its also marketable as 100% more blade than the competitors

 

[Saltchuck]

Triple edged razors have been tried, but they didn't catch on. One such is described under US Patent # 4534110.

http://www.patentstorm.us/patents/4534110/claims.html

I guess the idea was that if one is good and two better, then three would be better still. Sort of like what Gillette has been doing with cartridge razors, but in a different dimension.

I seem to recall seeing a picture of a British triple edged razor too, but I'm not sure about that.

 

[bluefoxicy]

This is obvious.

The DE razor Gillette invented was amazing. The blade sits at a 90 degree angle with the handle, centered, symmetric across at least two axis (and thus, across four-- being horizontally and vertically symmetric means symmetry across the diagonals as well).

That is to say, the entire razor, looking top down, is symmetric in eight directions (corner to corner, side to side) on one plane.

This makes the ergonomics of utilizing the whole device rather intuitive. Shifts in the razor's balance become obvious, and you get tons of feedback from its motion, pressure, and surface interactions (drag) with your face. You can feel if you push too hard, you can feel differences in the lather and blade, you can feel if the unit tilts.

The trade-off was, of course, bulk; the single edge razors had better maneuverability under the nose.

 

[klm099]

a double edge can warp sides 1 and 2 appx. equally and maintain the same degree off center

if you were to add sides 3 and 4 it would require a perpendicular stress to the one created by the warp of sides 1 and 2

i don't think a thin sheet of metal would hold up well enough to give a safe and dependable shave after the warping the blade in opposite directions

the double edge was a great marketing tool used by king gillette as well as making common sense, we were once a sensible nation
ken

 

[WinstonSmith]

I don't know the full history, but I think a lot of it was marketing on the part of Gillette.

Ads from that time period emphasized that there were two cutting edges, and 10 cutting edges per box. The idea seemed to be that having two cutting edges meant the blade should last twice as long as a Single Edged blade.

(oddly this doesn't seem to be true, as a typical DE blade lasts just as long as the Single Edge blade used with the competitor to the Gillette razors: Gem; although the Gem blades are thicker, and as such perhaps capable of holding an edge longer.)

I remember hearing that the degradation of a razor blade was not so much down to dulling from cutting hair, but from rust along the blade's edge. Tried a little experiment that seemed to bear that out.

When I first started using a DE (back in the dark ages of a few months ago), I only ever used one side per shave. Tried to keep track and use the other side the next day, but on a lark I tried just using one side up and then switching. The unused side was as dull as the used side.

It actually took watching Mantic's videos before I understood that you just flip the razor over once the one side is full up. Sometimes the most obvious things escape me.

 

[gurana]

a double edge can warp sides 1 and 2 appx. equally and maintain the same degree off center

if you were to add sides 3 and 4 it would require a perpendicular stress to the one created by the warp of sides 1 and 2

i don't think a thin sheet of metal would hold up well enough to give a safe and dependable shave after the warping the blade in opposite directions

the double edge was a great marketing tool used by king gillette as well as making common sense, we were once a sensible nation
ken

oh yeah, duh! I guess having the edges that curve sharp too would be no good. Though, now that I think about it, I did see a razor posted here once that looked as if it were supposed to fit circular blades... I never saw any blades for it, but strictly speaking it would've been single-sided, though I'm guessing it was a full 360 deg. of shaving.

 

[Hansel]

slice open a nose

Guess what I just did...

 

[michiganlover]

Guess what I just did...

Me too, I hate to admint it, but I have gotten sloppy enough on occasion to slice my nose open, not with the blade itself, but with the part of the blade that typically sticks out the end of the razor past the endcaps!! It bled like crazy!!

 

[_JP_]

Forgive me if this is being posted in the wrong place. Why do Double Edge safety razors have two sides? A total noob question, but I wasn't sure how to search for the answer yet.

I have been switching sides, because... well there were two of them so why not... I was thinking there must be some reason.

Single edge blades were the first on the market. Putting a second cutting edge on a blade so that you can get twice the use for the price of one was a stroke of genius.

 

[Telecaster52]

oh yeah, duh! I guess having the edges that curve sharp too would be no good. Though, now that I think about it, I did see a razor posted here once that looked as if it were supposed to fit circular blades... I never saw any blades for it, but strictly speaking it would've been single-sided, though I'm guessing it was a full 360 deg. of shaving.

was it one of these?

 

[dpmtherrien]

They had to do something with the other side.

 

[EFaden]

I'm going to vote for efficiency. They are making the effort to make the blade and using the materials anyways... may as well sharpen both sides.

 

[gurana]

was it one of these?

YEAH! Someone on here scored one, not really knowing what it was, as I recall.