"Shaving Sharp"-- Practical value or parlor trick?

BubbaGump said:
I would probably draw the line at actually trying to shave with a knife. Although its semantics and a razor or shaving blade is technically a knife blade, there is a reason they exist and people don't put on the morning coffee, lather-up and grab their pocket knife, even a very sharp one. Although the phrase is often used as a metaphor for extreme sharpness, the only thing as sharp as a razor is another razor. They make them for a reason.
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This is a good point[emoji2] I used a zdp dragonfly. The point made it a little risky, but I don't have an actual folding razor yet. I figure, when I get good and consistent then it'll be time to get one.
 
Parlor trick of course! But I sooooo love pulling that trick off!

But only when I have time to do it mostly with a new knife. Whenever I have to do a batch sharpen I usually shoot for a medium toothy edge as that what generally works best around the house for me. I find that I can keep most edges reasonably sharp with a hone or a strop for quite some time. But when I do it that way I always end up with 7 or 8 knives that I will eventually have to batch sharpen and it's like that meme... Ain't nobody got time for that!
 
In normal day to day use, I don't find "extreme sharpness" to present much value. Good blade geometry lends a helping hand much more than sharpness does.

However, for certain tasks I find that the sharpest blade presents a huge advantage; i.e. leather work. When I'm working leather, blade geometry isn't that important since I'm only making very shallow cuts into the hide. Maximum sharpness presents a huge advantage in this situation.

There is also another scenario where excellent blade geometry and maximum sharpness are important... Shaving:)
 
I shave with my knives. It gets touched up when no longer shaving well.
When used for daily tasks (packages, paper, rarely cardboard), the smooth feeling gliding through is satisfying. So I keep them at that level.
 
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Personally I am happy with easily slicing (not tearing) printer paper sharp and seldom go to shaving sharp. But if that is what you like, go for it.
 
Just one more thing in knife life to be OCD about....

I sharpen until I can easily make S-cuts in phone book or newpaper. After a while, even that becomes somewhat of a "skill" game--more in technique than actual "sharpness." Maybe that's what you mean by a parlor trick.

I like to keep a toothy working edge from there. Extreme sharpness is not my goal. I mean, where does it end? :)

I like a polished edge via strop and compound, but do not associate polished with "sharpness."
 
"Shaving sharp" is just a point of reference to me. It's how I know the knife is sharp enough to easily cut whatever I'll need it to cut. I keep all of my carry knives shaving sharp with a durable 20 DPS edge (or a 15 DPS edge with a 40 degree microbevel), as per my preference. Like Blues Bender said, however, geometry is more important.
 
It was mentioned several times in this thread that polishedness has little to do with sharpness. However, if we look at the physics, isn't it true that a polished edge will have less dragging when cutting/slicing through things and hence the knife is sharper? Of course, we will have to define "sharpness," which I see as the amount pressure that one has to apply to push the blade through the object that is being cut. If we agree to this definition, then the sharpness of a blade does seem to be correlated to the polishedness of it blade.
 
Jason B. said:
My edges are "razor sharp" at 300 grit. You don't need to polish an edge to make it sharp, just make sure you remove the burr. Sharp is sharp, how far you refine it is up to you.
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Bingo. Unless there is a seriously messed up edge to reprofile I can get a shaving sharp edge very quickly ~10 min, sometimes less. If I want to refine it than I spend a bit more time..
 
Razor sharp in my mind is equal to a utility razor.

If you wanted to say your blade was "sharp as a straight razor" then I guess that's what you would say.
 
I've found there are some pretty simple ways to make an aesthetically pleasing, shaving sharp edge equally durable. What I've been doing lately is the mousepad convexing method using lapping film ranging from 12 to .3 micron, then microbeveling that convex edge on edge pro choseras up to 10k grit, then balsa strops up to .25 micron. Leads to a hair splitting edge with a nice, clean apex, while still retaining a lot of the strength of a convex edge.
 
Knife sharpening is a highly useful skill, no doubt!
But while I admire people with the chops to sharpen a knife to shaving sharpness and beyond, I have neither the skill nor the need for that level of excellence.
 
A sharp knife is practical
A dull knife is not.

A "shaving sharp" knife is thus practical, more then just a parlor trick, but not necessarily a necessity, and ergo can be just a parlor trick if done without necessity but just to show off...

As bluesbender pointed, when working with certain mediums, shaving sharp can be quite the difference maker; scoring leather and slicing tomatoes comes to mind... However in other mediums, geometry and a sturdy "working edge" are more beneficial then whittling hairs only to create a less sturdy edge more prone to chip or roll...

When I sharpen my knives, I test whether they will take hair off my arm to know if they're acceptable to my standards, not "shaving" though, but a step away I guess... My kitchen knives I'll take to shaving sharp, and maintain with a ceramic honing rod, and they'll get resharpened when they no longer take hair with ease...
My work knives and hard use knives however, I'll lean more towards a convex edge, and maintain with a hanging strop, and while they won't take hair for as long, they'll continue cutting quite well for quite some time after they stop taking up hair easily... They aren't "shaving" sharp, but they're still pretty "cut something" sharp, and they'll hold that working edge longer then a "razor edge", and greatly reduces the risk of chipping or rolling during hard use, helping to ensure my knife will perform the task at hand, and not leave me s.o.l.

My casual knives can go either or, most i would say are kept "not quite" shaving sharp, but will still take some hair off your arm pretty easily. Others will scrape up dead skin cells more then hairs, but rest assured will break down cardboard boxes, and/or whittle chunks out of wood for a good amount of time before losing that edge...
 
sharp_edge said:
I... Of course, we will have to define "sharpness," which I see as the amount pressure that one has to apply to push the blade through the object that is being cut. If we agree to this definition, then the sharpness of a blade does seem to be correlated to the polishedness of it blade.
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I wouldn't agree to that definition at all. Way too simplistic. Cutting is not only about push cutting.
 
marcinek said:
I wouldn't agree to that definition at all. Way too simplistic. Cutting is not only about push cutting.
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OK maybe I was not careful enough with my definition. But even if we consider slicing, isn't it also true that a polished edge will have less dragging and hence require less effort? Push cutting and slicing are the two ways of cutting using a knife as far as I can think of (and let's forget about prying for a moment).
 
In slicing cuts a coarser edge usually outperforms a polished edge. It is in effect serrated, just at a very small scale. A well apexed 400 grit edge will sometimes push cut with less pressure than a refined polished edge due to the tiny points biting in under very low force because the force is concentrated on just the points.
 
sharp_edge said:
OK maybe I was not careful enough with my definition. But even if we consider slicing, isn't it also true that a polished edge will have less dragging and hence require less effort? Push cutting and slicing are the two ways of cutting using a knife as far as I can think of (and let's forget about prying for a moment).
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No. Not really. A less polished edge would have microserrations that may make cutting easier.
 
Coarse edges trump polished edges in most all cutting tasks unless the specific task requires a very fine sharpness, chisels, straight razors and Sushi knives come to mind in that case.

Shaving sharp is not a parlor trick and needs no fancy stones, it's the baseline of sharpness because regardless of the grit you sharpen to once you have formed an apex and removed excessive burr the edge should at least scrape a patch of arm hair off.
 
I like having one blade on my stockman shaving sharp because man does it carve wood nicely. Anything else as long as I can cuz harder wood when it's sharpened its find.
 
Jason B. said:
Coarse edges trump polished edges in most all cutting tasks unless the specific task requires a very fine sharpness, chisels, straight razors and Sushi knives come to mind in that case.

Shaving sharp is not a parlor trick and needs no fancy stones, it's the baseline of sharpness because regardless of the grit you sharpen to once you have formed an apex and removed excessive burr the edge should at least scrape a patch of arm hair off.
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Agreed. Hair scraping edges can be had off of the DMT XXC with decent technique and care with minimizing the burr.
 
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