What's your telltale way of knowing sharp?

[Heirphoto]

I usually just sharpen till I wind up cutting myself then call it good enough

 

[brancron]

My quick check is to see if the edge will “catch” arm hair easily (but I don’t go so far as to actually shave it off). I usually check on both sides of the blade, because if it catches on one side but not the other, it can mean a slightly folded apex or a burr that needs removing.

 

[helobite]

I can tell the sharpness of an edge by feel. I have been doing this for enough decades to have an idea of what sharp feels like. But the real test is a Roma Tomato. If the knife slices a Roma Tomato, I consider it sharp for my purposes.

even 440A will cut well, if you know how to sharpen it.

 

[sgt1372]

It's not scientific but I just run my thumb laterally (perpendicular) across the blade (w/o cutting it).

One thing I notice is that until the knife edge bevel is even, there's always a dull side and sharp side to the blade which tells me which side needs to be sharpened further. When it feels "sharp" on both sides, I'm done.

Been doing it this way all of my life. Works well enough for me.

 

[Chowser]

I'm a sharpening noob, but enjoying learning. I've spent a good bit of time working on my Native 5 in s90v, and it is currently my sharpest knife, like 'tingle in the base of your spine when a finger gets near it' sharp. I can see how chasing ever-sharper edges could become an obsession.

 

[cabfrank]

After reading this thread, I am convinced that most of us are crazy. I am happy to have learned about the three finger test, and will be going through my knives today, with band aids at the ready, just in case.

 

[me2]

Everyday edge test is slicing a plastic grocery bag or catching hair on the back of my head. Show off test is filleting letters off printed pages.

 

[ivonrei]

You know those envelopes full of coupons you get in the mail? I use those to test my freshly sharpened edges. I also run the edge across my fingernail to feel for any imperfections

 

[Applecider3]

It’s sharp if band-aid needed, scary sharp requires stitches, also cuts hair on way in and out....

 

[Bigfattyt]

one of my sharpest knives was my first self made blade. Ugly sucker. Made mostly with hand files. Finished on a 1x30 grinder, which ruined all the nice clean lines I had painstakingly put in.

Flat ground to convex edge. For some reason it is just stupid easy to get laser sharp.

I had butter fingers with it. It cut to the bone (bone made a little dull spot on the edge). I am confident that if it had been on the joint, the thumb would have fallen off.


Severed a nerve, cut a 180° arc. Still have permanent nerve damage in the dominant hand thumb. Right at the spot that drops a mag, slide release, etc. Also right where I grip a bat, sword, etc.

 

[ADBrown]

For those who shave their arms. You could be opening yourself up for a nasty infection like MSRA. I don’t even shave my face anymore.

Somewhere I read a bulletin sent out to fire stations telling the chiefs to tell the guys to stop shaving their arms. I guess that’s a thing now? Among the younger body builder types and it was causing a spike in those type of infections.

I’m unfortunately at the age where my skin is thinning quite badly - enough that just sliding my hands into a tight jeans pocket will lift the skin and leave a bloody flap. I’ve ruled out arm hair shaving because I don’t want to filet my forearm. I’ve switched to plucking a beard hair and running it across the blade to make sure it will at least split the hair if not popping it in two.

 

[T.J. H]

I keep a ULINE catalog for testing sharpness. Once I can cleanly slice a page, it’s good to go.

 

[yoko]

Light touch on my middle finger, my hands are very calloused from work and I can tell by the "grab" I feel

 

[Bob Denman]

I usually just sharpen till I wind up cutting myself then call it good enough

We must have gone to the same knife sharpening classes!
But when that doesn't work: I tackle some forearm hair, and see what happens...

 

[Diabloman]

shave the hair on my arm or slice a piece of paper.

 

[DavidABQ]

I simply try cutting a piece of note or printer paper.

 

[blanex1]

ether I youse phone book paper or shave my arm hair, most of time this works for me.

 

[CHNeal]

I just run my thumb across the blade as I have for 50 years now. Feels sharp I'm done, go back to work. When it stops cutting as I need I make a pass or two on the sharpmaker or coffee cup If I'm at work.

 

[EngrSorenson]

Wow, 1 and a half year old thread, but I’m glad it came up again.

Ever have a blade that you got nice and sharp that you tend to use another knife to keep that one as an “Edge Queen”

G2

I maintain all my blades to roughly as sharp as I can get them, so if I thumb another blade I can calibrate my expectations for feeling a burr or apex. I need to do that once in a while or else my expectations diminish.

If I’m really suspicious of an edge, I’ll turn off the lights and run my flashlight beam along the edge. If I see a shine I’ll get to work on it.

If I’m whittling, I’ll shave some end grain and see if there’s any streaks.

Also, whatever potato chip bags are made out of (such as Cheetos) is a good test medium, too, as the blade tends to rip the bag if it catches. It prevents me from actually cutting in the case of a catch.

 

[Gary W. Graley]

I'm still in the paracord push cutting camp, and my Spyderco Tenacious in S35vn laughs out loud at paracord or about anything that comes near the edge

I did an acid etch and stone wash on the blade so now it has this look to it but boy, is it sharp!

Untitled by GaryWGraley, on Flickr

G2