Why Not Razor Sharp?

One reason for my lack of interest in carrying so sharp of a knife is I know I would end up cutting myself badly with it.

It's also beyond my current sharpening abilities. :)
 
Buck268 said:
Now I know conventional wisdom says a dull knife is more dangerous blah blah blah. In my personal experience (though I hate to admit it), I'd found it not so true. I'vecut myself far more often on very sharp knives than on those which lack a good cutting edge.
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Yup, me too. Over-sharp can be dangerous, myths notwithstanding.

I only sharpen to the point where it needs to be. Anything more and it's dangerous plus you're losing edge retention.
 
Buhbuhbonky said:
Yup, me too. Over-sharp can be dangerous, myths notwithstanding.

I only sharpen to the point where it needs to be. Anything more and it's dangerous plus you're losing edge retention.
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Angle determines edge retention, not what grit you sharpen with.
 
that's what I was referring to. I assume "razor sharp" means re-angling the blade.

Hell you can polish a 40-degree blade all day and it's not going to be super duper sharp. For that you need to knock it down to 18 or less, like a japanese kitchen knife.
 
Buhbuhbonky said:
Yup, me too. Over-sharp can be dangerous, myths notwithstanding.

I only sharpen to the point where it needs to be. Anything more and it's dangerous plus you're losing edge retention.
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Could you elaborate, because what you state contradicts the experience of myself and others. I am interested in learning how a duller knife can hold an edge longer than a sharper knife, assuming no variables like different geometries, steels or heat treats.

that's what I was referring to. I assume "razor sharp" means re-angling the blade.

Hell you can polish a 40-degree blade all day and it's not going to be super duper sharp. For that you need to knock it down to 18 or less, like a japanese kitchen knife.
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If you are referring to edge angles, then why not word your post as such? Using words to describe the angle of sharpening and the degree of sharpness itself interchangeably as many members here do has created confusion over what the words actually define. Angle and sharpness are two unique concepts of knife sharpening.

I can make a 40 degree knife whittle hair, and can make a video to document such. If you mean that a 40 degree knife sharpened to this degree will not cut as well as the 18 degree knife, I agree fully.
 
whatever, it's just an internet forum.

To me, "sharpening" is actually removing a fair amount of metal from the blade, usually when you reprofile the blade or when you completely redo a damaged or *extremely* dull blade. Honing or polishing or stropping happens when you smooth out an already sharpened blade.

When you get your new UmbraOps DeathDealer Tanto and bring it home and it's not sharp enough for you and you take out your super fine ceramic rod and pass it a few times on the thing, you're not really "sharpening" it, you're merely honing it. Same if you do it with a buffing wheel or leather strap or honing steel or whatever.

So if somebody says to me that he sharped his knife to a razor's edge I envision him reprofiling the blade to a very acute angle.

If he says he buffed or polished the edge until it was real sharp then that's something else.
 
Buhbuhbonky said:
whatever, it's just an internet forum.

To me, "sharpening" is actually removing a fair amount of metal from the blade, usually when you reprofile the blade or when you completely redo a damaged or *extremely* dull blade. Honing or polishing or stropping happens when you smooth out an already sharpened blade.

When you get your new UmbraOps DeathDealer Tanto and bring it home and it's not sharp enough for you and you take out your super fine ceramic rod and pass it a few times on the thing, you're not really "sharpening" it, you're merely honing it. Same if you do it with a buffing wheel or leather strap or honing steel or whatever.

So if somebody says to me that he sharped his knife to a razor's edge I envision him reprofiling the blade to a very acute angle.

If he says he buffed or polished the edge until it was real sharp then that's something else.
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Where I say razor sharp, I mean a knife edge properly sharpened to the point where it can be used to shave one's face. This does not specify edge finish, edge angle, blade steel etc, it merely is a point of reference describing what is "sharp."

Still though...

How does sharpening or honing, however you define them, decrease edge retention in a knife blade?

How are 40 degree blades unable to get sharp?
 
A razor edge is so thin that it will "roll' over very quickly thus making the cutting edge less efficient. Thus when someone "strops" the edge it is removing this "rolled edge". I sharpen my knives at 40 degrees and can shave the hair off my arm. I wouldn't think of shaving my face with it though, that's what razors are for. ;)
 
Buhbuhbonky said:
that's what I was referring to. I assume "razor sharp" means re-angling the blade.
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Usually "razor sharp" is just a meaningless expression. I've seen a couple of makers use the word "razor" to mean nothing more than that the blade isn't serrated.

If you want to actually use a knife as a razor then yes, you will want a slim angle of attack.
 
Buhbuhbonky said:
that's what I was referring to. I assume "razor sharp" means re-angling the blade.

Hell you can polish a 40-degree blade all day and it's not going to be super duper sharp. For that you need to knock it down to 18 or less, like a japanese kitchen knife.
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I can whittle hair with my vic sharpened to 40degrees lol, a 18degree knife would cut better though.
 
For around 50 years I have sharpened every knife I touch as sharp as I have time for. Unless I am in a crazy hurry (usually that means I have to sharpen 50 knives in an evening) I reprofile them all to 10 degrees per side (20 degrees included angle). Razor sharp has always been my standard. If a knife won't shave I consider it a failure. That is one of the reasons that I don't like certain alloys. I would never consider an EDC that wouldn't shave. It is a dangerous abomination. What kind of idiot can't figure out how to manage his own razor?
 
Once a good edge is established it's easy to keep them working (read, pops hairs) sharp even after some decent cutting jobs. My old 710 I used as a worknife when I was an electrician cut copper wire, trimmed flash off of steel tubing, stripped cable, cut fiberglass insulation, cardboard and plastic shipping wrap on a daily basis. All it took to restore the edge at the end of the day was a couple licks on a diamond rod followed by a quick stropping, and it was ready to go all over again. It did need to have the back bevel reground once in a while to keep the cutting edge suitably thin but that was only once a month or so.
 
Why do I feel like I'm talking to a brick wall?

Why is it so hard to understand that a blade sharpened to a very acute angle (<20 degrees) will lose its edge faster than a blade at a more obtuse angle (40 degrees), all else being equal? :confused::confused:

shallow grind = Thin metal = weaker edge

I don't understand how y'all can't get this concept.
 
They understand that concept easily - they also understand that even after the very edge is weakened, the overall profile of the knife is very slim in comparison to the one with the wide edge - and it will continue to outcut the wide angle for a while. I can get a wicked edge on a 40* overall angle - not as good as a 30* overall or a 20* overall, but still much sharper than the factories put out several times over.

In fact, juuuuust for you:

http://www.youtube.com/watch?v=1SFG9-6Bmp0

http://www.youtube.com/watch?v=zW8bc7W3Qik&feature=user

http://www.youtube.com/watch?v=IMpS-pKQlzI&feature=user


There is a LOT more geometry involved than just the angle of the very edge.
 
well that's awesome. But then the whole concept of "sharpening" it to the best ability of the blade to hold an edge is wasted isn't it?

So you're saying you'd rather be cutting with a blade that has a tiny angle that has dulled, more than a wider angled that still is holding it's edge?

This makes no sense to me. Nor does reprofiling all your tactical knives to a "razor" edge of 10 degrees???? And then letting those edges dull????? What??

I don't get you people. Unless you're going to shave, literally shave with the thing, leave the poor blade alone. Hone it if you must, but leave it alone.

I'm going to start calling this "bubbaing" a knife. Like those folks who take great old SKSs and stuff and add all sorts of "tactical" things to them and ruin them..? Same with people who take a perfectly usable 30-40 degree blade on a folding knife and whittle it down to 14 degrees and then complain when it chips and dulls.

Silly, verrry silly.
 
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