When is a knife sharp enough, and how to you test?

[dawsonbob]

For the most part I'll get a blade pretty sharp with the DMT extra fine, and maybe give it a couple of licks on the strop, and that's more than good enough for most day to day stuff. Sometimes though, I get carried away with the "just how sharp can I get this sucker?" syndrome, and then I get into it. Do I need it that sharp? No, I don't... but it sure is fun sometimes.

 

[eKretz]

Heh, actually, that quote is Voltaire's...he's French. But good point!

 

[Hawkings]

It is very possible to go beyond 2" from the point of hold on newsprint. My knives that are sharpened to .05 microns go well beyond that while easily whittling the tiniest of curls from hair. It just takes practice. A better test is pushcutting the yellow pages. When you get over 2" from the point of hold it is very impressive. Something to remember about pushcutting newsprint is how different it can be from paper to paper. Try to use the same particular newspaper if possible and practice holding it with your 2 fingers so it doesn't add tension to the paper. Pushcutting newsprint requires making sure you have thoroughly deburred your edge, as your shaving edge that won't pushcut well most likely has a burr.

Mike

I would be very happy if you could show me this in a video, as we might have a very close, but not identical, definition how to make a push cut 2" away.

And in all honesty it would be nice to have a clear and clean proven standard, to which we could refer, when discussing these things.

 

[stitchawl]

The Russians had a saying, "Better is the enemy of good enough". The application of that to knife sharpening is, after a certain point, it crosses the line into obsessive behavior.

I can get a knife sharp enough, but I still try to extract that extra level of s, often in vain. A Seki-city made "Damascus" Santoku knife I have came sharper than any knife I've ever seen. Push cutting newpaper like it wasn't there.


Does an EDC need to be that sharp? No. But you always have to try

We often go to Seki City as it's only a short (less than 2 hours) and pretty ride from my house by motorcycle. We had plans to go this weekend as the second Saturday and Sunday in October is always a big festival day there, with many different demonstrations going on all around town. Huge outdoor cutlery market on one of the streets of the town with incredible prices on knives and stones! Even on non-festival days many of the workshops are open to tourists, and it makes for a great 'destination' for a day's bike ride!

Stitchawl

 

[PBJSIII]

All I know is that I used my 1919-1940 Case Scout that was my Grandpa's at our family reunion yesterday. It cut sausage and steak like a hot knife through butter.

When I used a napkin to wipe the blade it made a slice in the napkin and in my thumb.

THAT thing is SHARP!

I hope that all of you might get one that sharp.

 

[gunmike1]

I would be very happy if you could show me this in a video, as we might have a very close, but not identical, definition how to make a push cut 2" away.

And in all honesty it would be nice to have a clear and clean proven standard, to which we could refer, when discussing these things.

Well, I need some practice at using my camera while push cutting newsprint, as I don't have a tripod. Plus, i've never uploaded a video. Either way if you search a couple years ago there was a lot of threads where we discussed methods of pushcutting newsprint. My method is to use my left hand to hold the paper between my thumb and forefinger, hold the paper as still as possible, then push the knife edge straight down into the paper. If it folds it fails, if it cuts it passes. When I was a few months into sharpening 2" from the point of hold seemed impossible except for Spyderco edges that cut over 3" from the point of hold. Since then my skills are way better due to my OCD and I use finer abrasives that allow the knife to easily surpass 2" from the point of hold (though at Spyderco medium you can surpass 2" from the point of hold with practice). I have learned that just because I am not capable of getting edges that are sharp enough to do some pretty extreme feats not to doubt that other people can. I think with more practice and possibly different techniques and abrasives you will find your edges easily able to surpass 2" from the point of hold. Get a 100x lighted microscope (dirt cheap at Radioshack) to check for burrs, and once you have no visible butting at that magnification see how your edges pushcut newsprint. The difference is huge, as I have found burr removal to be the key for truely sharp, long lasting edges.

Mike