What's your telltale way of knowing sharp?

[Gary W. Graley]

Not to crack open that complete can of worms, as there are tons of threads about how to sharpen a blade along with how to test for sharpness. But one thing that I seem to always fall back on is a quick and simple check to see if I have the edge fully to an apex shape and that's how well it press cuts down on paracord.

If it is sharp, it parts the paracord easily without any extra effort on the spine of the blade, IF the edge is not sharp, even if it slices paper cleanly or shaves hair, the very edge can still not part the paracord cleanly without some extra effort.

My friend @Matthew Gregory has a video showing some paracord FLYING apart as it is being cut with a freshly sharpened blade, I still think he some how inserted small springs inside the paracord as I have yet to duplicate such a feat

But, if an edge has the tiniest bit of roundness at the apex area, it will just dent the paracord, so for me, this has lately been my 'test' to see if I have the blade done.

I don't have a video of my doing that, but I did have this video showing opening a folder one handed and then slicing cleanly down through some paper, it's a Boker folder and lemme tell ya, it is one sharp cookie!!!

So, what are your benchmark ways of knowing you are done with sharpening a blade??
G2

 

[Halfneck]

I take a sticky note and put it on the edge of my desk with about half sticking off. If I can slice clean strips back and forth I am content.

 

[JokersFaceLifter]

i shave off a layer of skin on my finger, just enough to feel the "catch" either that or i plane a little bit of wood

 

[comis]

For me, it would be slicing/push cutting thru thin receipt paper or phone book paper, how easy it is to slice/cut thru and the sound it makes.

 

[Gary W. Graley]

Ya receipt paper is a good method too, one my wife also hates
G2

 

[Prester John]

Similar to others: cutting paper. Sticky notes, notebook paper, receipts, etc. If the knife slices quickly and smoothly with no snags, I'm happy. (I've also shaved arm hair, but I can only do that so many times!)

 

[Gary W. Graley]

Yes, arm hair, I've told this before but it's still funny, during one hunting season I had a lot of knives to sharpen for friends at work, a lot, and my entire left arm from shoulder to knuckles was bare, completely bare....my wife did not notice until one day I folded my arms across my chest as we were standing waiting on something and she saw the stark comparison of one bare and one hairy arm...she made me PROMISE to never do that again and...I have kept that promise....I have never completely shaved my arm since....not completely

Also she did not care that I told her as an 'Merican I have the Right to Bare Arms....did not go over so big
G2

 

[jfindon]

How easily it catches my nail, and then if it shaves both with and against the grain with minimal effort. Anything else is just bragging rights and I don't really care about.

 

[ruddyduck]

I've gotten to where I don't test sharpness anymore. If I can get a burr with a 1500 diamond stone, I know it's damn sharp. I then strop, and I'm done.

 

[Korean Hog]

Normally: check with the thumbnail while sharpening.
Check for shiny spots on the edge with a bright light when the whole edge catches my thumbnail.
Then slice a piece of whatever junk mail is laying around to make sure the edge is good.

I find paracord to be a good test as well. I've definitely had to touch up an edge I thought was good and sharp
when trying to cut neat ends to finish a lanyard or fob. IMO, without neatly cut ends you wind up with a melted gob of junk for the end of a lanyard when you fuse the ends.
I've also had a knife nearly refuse to cut a piece of paracord before a few passes on the microbevel and then it cut cleanly.

 

[DangerZone98]

Good ol’ paper method. It needs to glide across the paper without a hitch. Any hiccup and it’s back to the rods.

 

[soc_monki]

Cleanly slices paper towel is my top test. Bounty or Sam's club paper towels btw. If it's sharp enough to cleanly slice that, it will cut anything.

I also cut catalog paper, receipt paper, finger nail test, hair shaving (popping)... If it passes some or all these tests it's good.

 

[not2sharp]

It is good if it is sharp enough to cut what you need cut. Any sharper than that and you are unnecessarily wearing away the blade.

n2s

 

[scottyj]

I run my thumb down the edge. If it sinks in its sharp.

 

[AntDog]

If mine will easily cut curves in paper and shave hair they’re sharp enough for me. Nothing I cut needs a blade sharper than that.

 

[Pomsbz]

Receipt paper and arm hair. The latter will show if it's sharp but the former will also tell me if it's smooth along the length of the edge.

 

[EatingSarma]

Shaving some arm hair.

 

[abbazaba]

Magazine paper communicates a lot as my quick and easy method, for sharpness and trouble spots. Not saying I don't have bald arms and a hundred feet of diced paracord

 

[eugenechia1989]

By inspecting the edge under a bright light, either a flashlight or the sun if it's a sunny day. Oh, and the usual paper-cutting, shaving... But I'm trying to shave less as I'm not particularly hairy and I worry about the day where I really run out of hair. Haha.

 

[jfk1110]

When I first.picked up my billystrop by Stropman R.I.P., It opened my eyes to a whole.New level of sharp. It also led to all my extremities being hairless. Not a hair could be found on my arms or legs. At this.point I can tell by how the.blade feels as I pass it along the strop! So I now.have hair in all the usual spots!