Sharp vs keen - please help a non-native speaker understand

[Scrubby]

I hope you can help me with understanding the difference between 'sharp' and 'keen' for a straight edge.
When I translate online both get the same translation (Dutch: 'scherp').

After reading a lot of posts, SoS website etc. etc. I understand the difference as follow:
I have several straights, 5/8 - 8/8, ranging from full hollow to 1/3 hollow. When I really do my best on a 12k Naniwa (+ afterwards 150 laps on my Kanayama strop) I get them all to a similar "sharpness". Shaving with them feelt similar, as the face feeling is dominated by the similar harsh edges, leaving me with some minor irritation (in my case: I can really feel the burn from the aftershave).

Afer a few shaves (each time stropping 20 x on canvas + 70 x on leather) The face feel drastically improves; the razor glides more effortless over the face, i can navigate around the chin much smoother, it feels like the razor "knows" what is the haor to cut andwhat is the skin to glide over. Mind: the razors still cut very well, they did not lose some sharpness. In this phase I also start noticing differences between the individual razors: The leightweight 5/8 Full hollow is really feeling different from heavyweight 8/8 1/3 hollow. DIrectly after honing all these differences are much less noticable. As I understand it now, it might be the "keenness" of the razors that develops and causes both improved comfort + brings out the individual qualities of the the edge/razor.

Am I completely lost here I am I on the right track?
What do you guys think?

 

[ScottChapin]

I think the way we think of it, they’re the same, because our blades must all be keen.

Keen means sharpened to the point of cutting easily and readily. You can sharpen an axe and have a sharp axe, but it won’t be keen. A keen edge on an axe would likely chip and degrade while cutting wood.


Sent from my iPhone using Tapatalk

 

[camoloc]

I hope you can help me with understanding the difference between 'sharp' and 'keen' for a straight edge.
When I translate online both get the same translation (Dutch: 'scherp').

After reading a lot of posts, SoS website etc. etc. I understand the difference as follow:
I have several straights, 5/8 - 8/8, ranging from full hollow to 1/3 hollow. When I really do my best on a 12k Naniwa (+ afterwards 150 laps on my Kanayama strop) I get them all to a similar "sharpness". Shaving with them feelt similar, as the face feeling is dominated by the similar harsh edges, leaving me with some minor irritation (in my case: I can really feel the burn from the aftershave).

Afer a few shaves (each time stropping 20 x on canvas + 70 x on leather) The face feel drastically improves; the razor glides more effortless over the face, i can navigate around the chin much smoother, it feels like the razor "knows" what is the haor to cut andwhat is the skin to glide over. Mind: the razors still cut very well, they did not lose some sharpness. In this phase I also start noticing differences between the individual razors: The leightweight 5/8 Full hollow is really feeling different from heavyweight 8/8 1/3 hollow. DIrectly after honing all these differences are much less noticable. As I understand it now, it might be the "keenness" of the razors that develops and causes both improved comfort + brings out the individual qualities of the the edge/razor.

Am I completely lost here I am I on the right track?
What do you guys think?

I think the terms mean the same thing:

wicked sharp.

camo

 

[stone and strop]

Sharpness and keenness are the same thing IMO.
It is getting smoother over the next few shaves due to getting smoothed out on the leather.

 

[RayClem]

I have a coarse, old may white beard and very sensitive skin. To cut through my coarse beard, I need a blade that is very sharp or keen. However, I also need a blade that is very smooth so that is does not irritate my sensitive skin.

I have a set of Naniwa SuperStones and I also find that the Naniwa 12K can produce a sharp edge. However, I cannot shave off a 12K as the edge is very rough on my face. A Coticule will produce an edge that is smooth enough for my face, but not an edge that is sharp enough for my beard.

I have a few hones that will produce an edge that I prefer to the Naniwa 12K. That would include the Vermont Green Slate, the Greek Vermio hone, the Imperia La Roccia, the South African Zulu Greey and the Suehiro Gokumyo 20K synthetic. Natural stones vary in quality, so not every one will provide the same edge. The Gokumyo 20K will produce a superb edge, but it is quite expensive.

There are a number of people that hone on ultra fine lapping film used to polish machine parts.

A more reliable option is to use pasted strops to smooth out the edge after your hone it. I use a series of Cubic Boron Nitride pastes/sprays on nanocloth strops. Many others like using diamond sprays on balsa strops. A 12K Naniwa is about 1 micron partical size. Thus, to further refine the edge, you would want to use 0.5 micron, 0.25 micron, and 0.125 or 0.1 micron abrasive pastes or sprays. My Gokumyo 20K is equivalent to 0.5 micron so I could skip that pasted strop and start at 0.25 micron. It may be that you do not need to go as fine as 0.1 micron, but my face is so sensitive that I could tell the difference between 0.25 micron and 0.1 micron.

You might want to check out this thread by @Slash McCoy on how to use a pasted strop. His "The Method" procedurfe uses diamond pastes on balsa. A lot of folks love edges produced by The Method.

ttps://www.badgerandblade.com/forum/threads/how-to-use-a-pasted-balsa-strop.473580/

 

[kohalajohn]

The site Science of Sharp uses the words sharp and keen to mean different things.

Sharp does not refer to the edge, but instead refers to the width of the blade immediately before the edge, to that bevel which is an isosceles triangle. If it is described as sharp, that means this triangle is very thin. It presents less friction as the knife cuts through material, like meat. A wide triangle will create resistance as you try to slice through something. The actual edge may be wonderfully "keen" but in butchery that won't matter, as that fat triangle will make it hard for you to cut. You will perceive the knife as dull. Thinning the knife at the bevel area will make it cut meat better, even if you do nothing to the edge.

Keen refers to the edge itself and is what shavers are interested in. We are not slicing deeply through a roast beef. You will see on the knife discussion forums that sharp and keen are used to mean different things, as they are talking about butchery. On razor discussion forums all we care about is the edge, so we use the term sharp and keen to refer to the edge, and that's fine for our purposes. We all know what we mean.

So that's how Science of Sharp uses the terms.

 

[Gamma]

A sharp edge is a keen edge, and a keen edge is a sharp edge.
Some edges cut, and some cut better than others due to several non-mystery factors.
Sharp is keen and keen is sharp. End of story.

If need be, a data manipulator can 'prove' a razor blade is dull and a serrated bread knife is sharp.

Keeping it simple, an edge is a sum of its parts, apex condition, apex geometry, edge width, and so on.

Cutting efficacy is the point of confusion, and it can be as much related to the material, cutting angle, pressure/force, and cutting medium as anything else really. Ever try to shave with lather that is thick like paste? You might think your edge sucks. Nope, it's the lather. Well, the edge might suck but that's another story too - objectively though, too-thick lather can ruin a shave and many people think their edge is to blame.
There's nothing to do with sharp/keen in that scenario.

One does not need to create new definitions for existing terms to understand a sharp edge. Trying to force the sharp/keen technobanbble on people really only clouds the actual points that people need to understand. Throwing a pile of SEM pix into the discussion muddies the water further. Factually, I can take any pic anyone needs to support any argument. That's not science, it's confirmation bias.
Personally, keeping it simple has always worked best for me, esp in this arena.
Complicating it is counterproductive.

Now, sharp vs smooth - that's a legit topic.....

 

[xuzxuz]

@Scrubby

If you are getting uncomfortable after fresh honing, it could be wire edges or some such things.
As you use the razor (stropping on leather, contact with hair, friction against skin, etc.) those imperfections might be getting smoothed out, resulting in more comfortable shaves.

Re: Keenness vs Sharpness
Colloquially, they mean the same thing to Americans.
Scientifically, I don't think there is a standardized measurement tests either.
At first glance, there's only the ISO 8442.5 Materials and articles in contact with foodstuffs — Cutlery and table holloware — Part 5: Specification for sharpness and edge retention test of cutlery..

My interpretation of SoS website is something like this.

I admire the engineer's effort to provide some clarity. But I think it's the classic case of too much and not enough, as the last profile shows.

 

[Eastcoast30]

I believe that sharp and keen are synonyms. Most razors are sharp as manufactured; meaning they can cut. But they may not be shave ready as manufactured. What we are interested in here is not if the razor is sharp, but if it is shave ready. And that is another conversation.

 

[Atlantic59]

A keen edge is also a sharp edge, but keen implies something else besides -- suitability for a particular job or purpose. In other words, the blade has been sharpened so that it will work best for it's intended purpose.

 

[Tanuki]

As this thread makes very clear, sharp and keen do not have well standardized meanings.

The Science of Sharp site uses those two terms in a specialist manner, illustrated by well-processed and analyzed scanning electron microscope images that are quite amazing. It is unlikely that this work will be surpassed any time soon. Definitely worth any time invested by SR fans to read in depth. Go there.

Further, connecting blade images and honing/stropping procedures to shave effectiveness and aesthetics of course involves subjective judgement, difficult quantification and description of honing and stropping materials and procedures, differing types of skin, hair, nerves. And more!

Throw in steel formula, blank dimensions, tempering, grinding, and razor use/abuse history. Now address your shave results scientifically. Or write a poem. Just don't pick a fight.

I am happy to read posts taking either approach, ideally illustrated with a photo of a beautiful/ugly/new/used/unique SR! Or an SEM image. Or a cheap USB microscope edge picture.

 

[R7photo]

Newbi question
Seems some of these threads kinda merge
Is an good edge also defined as how long it last?

Is the best edge the first shave then degradation after that

My last shave seemed to debunk this as 3 shave on a Heljestrand razor seems like it got sharper than first shave,

Thx

 

[JPO]

If only there was a way to make the bevel taler and at the same time thinner behind the apex, without changing the spine thickness? One would be inclined to think that making the apex a fraction of a micron smaller and the thickness behind the apex thicker, by using “soft" substrates, charged with diamond, cbn etc would to some degree be giving up something in the pursuit of something else. Keen or sharp, you need both. The edge also needs to be up to the task it was designed for, and be suitable for the end user.
You need enough support behind the edge, but it is also a tradeoff between sharp and keen.
And then there is the smooth as an even more confusing factor on top.

How you define sharp and keen is to me not that important

 

[ylekot]

The way I understand it:
Sharp means it will cut, may or may not be intentional, may be jagged as a tin can lid or smooth as a finely honed blade

Keen means an intentional effort was put into the edge to make it suitable for a given task. As a previous poster stated a keen axe is not the same as a keen razor, but both are sharp.

 

[Eastcoast30]

I think it is just semantics. For a straight razor, the main concern is the ability to shave and to do it comfortably. Different steels and different grinds will feel different and behave differently on the face. You want something that works well for you. One needn't concern themselves with "sharp vs. keen". There have been a multitude of threads on this semantic.

 

[bluesman 7]

Keith has a new video addressing this to a degree.

 

[Brutus]

A keen edge is also a sharp edge, but keen implies something else besides -- suitability for a particular job or purpose. In other words, the blade has been sharpened so that it will work best for it's intended purpose.

Pretty much my take too.

A sharp edge can be uncomfortable while a keen edge mows the whiskers with ease, but goes with a measure of comfort about its job.

Coming straight off the stones an edge is sharp, after some stropping (with paste, if so desired) it becomes keen.


B.

 

[steveclarkus]

Keen also means to like something or someone as in, “ I’m keen on her”.

 

[steveclarkus]

Keen also means to like something or someone as in, “ I’m keen on her”.

 

[Slash McCoy]

If only there was a way to make the bevel taler and at the same time thinner behind the apex, without changing the spine thickness? One would be inclined to think that making the apex a fraction of a micron smaller and the thickness behind the apex thicker, by using “soft" substrates, charged with diamond, cbn etc would to some degree be giving up something in the pursuit of something else. Keen or sharp, you need both. The edge also needs to be up to the task it was designed for, and be suitable for the end user.
You need enough support behind the edge, but it is also a tradeoff between sharp and keen.
And then there is the smooth as an even more confusing factor on top.

How you define sharp and keen is to me not that important

Better to have the spine at exactly the optimum thickness for the bevel angle you want.