Definition of Scary Sharp?

Mar 15, 2001
I've been lurking for a while and have learned quite a bit about knives - this is a great site. However, I haven't seen any post that has actually defined what "scary sharp" is. Is it measurable (e.g., cut a free-hanging hair) or is it one of those "you'll know it when you feel it" kind of phrases?
I don't know about how others rate it, but for me scary sharp is a sort of literal fear thing. I've been puting shaving-sharp edges on knives for over 40 years. In all that time I have routinely checked sharpness by feeling the drag on my finger tips as I lightly scrape them against the blade edges. For me, "scary sharp" is the type of edge you get on a straight razor that I don't dare to check using my normal feel test. I still feel the edge, but in a much more delicate way. The slightest mistake and I'll get cut.

[This message has been edited by Jeff Clark (edited 03-15-2001).]
For me its when you stroke the edge with your thumb, and get a stange... 'thrill' when the hairs and the back of your neck stand up and you think "****, a little more pressure and I would have cut myself" then ten mins later you start to bleed. That is scary sharp IMHO.


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Welcome abosard Mark. There's no real test. It's just very sharp. Sometimes like the General said, the hairs on the back of your neck stand up.

Welcome aboard Mark.

There's no real test. It's just very sharp. Sometimes like the General said, the hairs on the back of your neck stand up.

My definition is that the knife is so sharp that a) it takes so little effort to cut/stab through material and b) you're so surprised that it does take so little that you take your time.
On the cig paper. Try taking a 1/4" square of tape and use it to tape a thread to the cig paper. Hang thread and paper and then cut it in half while suspended by the thread. Knife has to be sharp to do this one.
On Scary sharp. I consider a knife scary sharp when I can shave a sleeping mouse and not wake him up.
Been trying that some, now all my mice have insomnia!


(If that is Jerry Fisk, it is a real honor, sir, to share a thread.)
Scary sharp is when the hairs on your arm jump off in fear before the blade even gets to them.
I think M's answer is the standard definition!! It's true though

I must agree that testing with cigarette paper is the way to go. It's fun to watch peoples reactions when they carve up a paper with a "scary sharp" blade....


Hand Made Knives..High Tech Materials
I've always thought chainsaws were just about the most scary sharp blades.
Buy an Edge Pro Sharpening System and you'll know what "scary sharp" really is!
Scary sharp is when you just look at the edge and you start to bleed. Every once in awhile with the right knife and steel I'll get to scary sharp.I have a collection of various types of hones, both old and new. I seem to have had the best luck with soft arkansas first then to a harder stone, using Buck honing oil.I always seem to run out of Buck oil, so I tried a mixture of sewing machine oil and old "Marvel Mystery Oil"(an upper cylinder lube used by old automotive mechanics) mixed 50/50 to use on my stones, and it seems to keep the stones porus and float the steel particles away.Regards JIM
Normally, I think a knife is sharp enough if you cannot actually see the edge. But, every once in a while, I will get a knife so sharp it will scare the hair off a gnat's ass.
For every day use, if the edge will grab when run across my thumbnail, it is sharp enough.

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Scary sharp is an edge that will cut at the slightest touch. Like a brand new Chris Reeve Sebenza. There are knives out there that come sharp, but only a few come scary sharp.

[This message has been edited by el cid (edited 03-16-2001).]
Welcome to the Forums, Mark! You'll love it here!

Scary sharp is when you cut yourself, and don't feel it or even notice it until you see the drops of blood on your clothing or the floor.

Scary sharp is also when you feel the edge and get just a bit nervous, almost feeling like a sheeple, and don't want to "play around flicking it" while watching TV or doing anything else (which you normally will do with a 'sharp' knife), because you don't think it'd be a good idea with THAT sharp of a blade - 'just in case'.

Enjoy the forums!

Champions make improvements as fast as losers make excuses.
Bugs It is a pleasure to share the forum with you as well. I have learned a lot of information from forum members.
Mark, to my knowledge there is no measureable way to determine scary sharp. That is just when you get the "teeth" of the cutting edge just the right length for the given steel as well as the right length for the given steel and it is standing straight up.
Even though last week I made the sharpest knife I have seen. When I pulled the knife out of the sheath, the shadow of the knife cut the leg of the table off before I could turn the lights off.
I agree with champion. So sharp it is literally scary to use.

The first knife was probably used to cut stuff.