Straight sharpness vs DE question

[benjtaylor]

With a DE razor we would change the blade every few shaves, and I am presuming (but correct me if I'm wrong ) that it is because it loses its sharpness.

However with a straight, you keep the same one. You would strop it, but, if I understand what I've read correctly, that doesn't sharpen it but merely 'aligns' it.

So my question is how can a straight maintain its sharpness in a way that a DE blade doesn't?

Is it because a straight is a much bigger chunk of metal, or does a DE blade not actually blunt but merely become unaligned and if you bothered to strop that, it would be last for a long time?

 

[Lmarkow]

Hi, and welcome. I think the DEs are much thinner, so they don't retain their cutting edge as well. Stropping may prolong a DEs useful life, but I guess that's a bit tough to do on both sides. And they're cheap, so why bother?

I should mention, I think the DE's cutting angle is much more severe than the typical straight. I'm not sure that necessarily makes it "sharper" though.

 

[kcb5150]

I doubt they're tempered anywhere near as hard since they need to flex and not shatter. Injector blades don't have that design constraint and last a fair bit longer

 

[BroPeter]

A straight will need to be honed, or sharpened from time to time. The strop helps keep the edge. It's much harder to work with a very thin piece of metal to sharpen and strop. You could try flipping the DE blade to try and prolong it, but usually it's 4 -6 shaves then tossed and that all depends on the users hair.

Sent from my SM-P550 using Tapatalk

 

[bluesman 7]

I think that if one had an effective way to strop a DE blade it would last comparably to a straight between honing. I believe that there is an abrasive/sharpening component to stropping. Even though it is very fine

 

[alpster]

There were several gizmos sold over the years to strop DE blades for the purpose of extending their usable life. I think post war prosperity and automation drove the cost down to the point that it was more trouble than it was worth. I still occasionally see the blade stroppers at flea markets and antique shops.

 

[stoop]

DE blade stroppers have been marketed in the past. No idea how long they keep a blade going.

But yeah, DE blades are much thinner, softer, and more ductile than straights. As a consequence they are also (initially) sharper than the typically honed straight.

They are also conveniently disposable. These days when I use a DE (once a week for shaving my head) I'm one-and-done with a Feather. No need to try and make a blade you use once a week last more than that, really.

 

[bluesman 7]

Most of the DE strops have a very short length (6"). So it would take hundreds of laps compared to a 16"-24" razor strop.

 

[spoken36]

I think the DE's cutting angle is much more severe than the typical straight.

I would have thought so too, but here is a quote from Seraphim in a recent post: "A Feather AC Super Pro blade has a edge bevel angle of 25 degrees." Interesting stuff.

 

[global_dev]

a feather ac super is clearly not a DE blade..

 

[Kentos]

If one took the trouble to build a handle to strop a DE blade I can't imagine that it wouldn't prolong the edge. You would have to strip both sides, and dry off the blade every night to prevent oxidation. I have read that modern DE steel doesn't respond well to stropping but metal is metal IMO.

 

[spoken36]

a feather ac super is clearly not a DE blade..

Right.

But assumptions about disposable razor blade angles might not be very accurate.

I wouldn't have guessed 25 degrees for the feather ac super, would you?

 

[global_dev]

honestly, i dont knowits been a while since ive handled/examined a feather pro, but they are thicker with a small bevel, so i can get with that.

 

[stoop]

Meanwhile Feather's DE blades are the thinnest on the market, so you're both right

 

[spoken36]

Well, I certainly can't be right about this, because I demand rigidly defined areas of doubt and uncertainty.

Meanwhile Feather's DE blades are the thinnest on the market, so you're both right

 

[eKretz]

I think when LMarkow said that the "cutting angle is more severe on DE blades" he meant the angle that the blade is held against the face, not the bevel included angle. With a straight you can angle it to wherever you want and get very good efficiency and blade life. The DE drags the edge a bit more as they seem to hold the blade a bit steeper and your stuck with whatever angle the razor holds the blade at, which negatively affects blade life. That, the fact that they are very rarely stropped these days and the softer blade make for less longevity.

 

[stoop]

I have no experimental basis for this but I am willing to bet that the metal used for DE blades is way more ductile than almost any straights edge metal.

 

[Lmarkow]

I would have thought so too, but here is a quote from Seraphim in a recent post: "A Feather AC Super Pro blade has a edge bevel angle of 25 degrees." Interesting stuff.

Careful. He's a known trickster.

 

[Lmarkow]

I think when LMarkow said that the "cutting angle is more severe on DE blades" he meant the angle that the blade is held against the face, not the bevel included angle. With a straight you can angle it to wherever you want and get very good efficiency and blade life. The DE drags the edge a bit more as they seem to hold the blade a bit steeper and your stuck with whatever angle the razor holds the blade at, which negatively affects blade life. That, the fact that they are very rarely stropped these days and the softer blade make for less longevity.

I'd like to be able to take credit for being so smart, but alas, no. I meant the V angle.

 

[bluesman 7]

Wasn't there some info about feather blades being 'plated' with a polymer or something to form the actual cutting edge. In which case comparing bevel angles to steel edges is really apples and oranges.