The rubber band test

UffDa

UffDa

Gold Member
Joined
Sep 11, 1999
Messages
42,596
I was messing around with my GSO 4.1 and remembered the rubber band edge test. You hold the knife vertically with the edge towards you.
Hook a rubber band around the blade and stretch it as far as it will go without breaking it. Let it go and watch what happens. If your edge is
sharp, it will cut the rubber band. If it is really sharp, you should end up with 3 or 4 pieces and maybe several nicks in the band. I saw a slow
motion video a long time ago. The rubber band waves around and folds over on itself on the way to the edge. Different bands do different things.
A long skinny band will usually cut into more pieces.

WARNING! It's a good idea to hold the knife firmly. You wouldn't want it to fly out of your hand, would you? If you kill yourself, don't come running to me.

Sce75Xh.jpg
 
I'd never heard of this test before. Luckily I just grabbed a huge handful of rubber hands last time I was at the PO, they are no more. My Sebenza made about 6 pieces out of each and even my needs-sharpened GB got a few pieces from each.

Very cool little test.
 
It's probably not a good idea to do this with a slip joint folder. Just saying. :D
 
Quite the good time! Thank you. I tried it with my Spyderco Phil Wilson South Fork. Being a bit slow, it took me a minute to realize that we're stretching it over the spine and not the sharpened edge. Now excuse me while I go find all the little pieces of rubber band on the kitchen floor. Thanks again, that is fun. Mike
 
Well here's a test I've never heard about before. Just tried it and was surprised by my results.

First up was a Mini-Skirmish with a stock edge and it was surprising.

2014-04-04142249_zps00c18e58.jpg


Next up were the knives with my edges though.
And the clear winner for me was the M4 Mini-Grip. I'm not sure what happened but it turned the rubber band into 4 pieces of rubber! I'm pretty sure the two Spyderco each split the rubber band into three pieces but I couldn't find them. Definitely heard more than two sounds when it cut.

2014-04-04142641_zps16b79539.jpg
 
Hmm good suggestion. I'll have my ex-girlfriend try it with a katana :D
 
My ESEE 4 didn't cut sh*t. For three nights I sat here and reprofiled the blade on my ESEE 4 to a convex grind and thought it had a sharp edge but it didn't cut the rubber band once, even after multiple tries. I hate this f*&^%$# knife. The 1095 is too thick and too hard to sharpen. At least my CS Trail Master Chinese copy cut every rubber band at least in one piece.
 
Last edited:
My TSF Beast in M390 (Jim Allen's creation) did very well, I thought. After the pic, I found one more long strand on the floor, so I think this knife produced six pieces. :) It's only fair to say that the blade was later reprofiled, sharpened and polished. However, this is my 3rd TSF Beast from Jim, and this knife in M390 is very hard to beat.
Note that the pivot is showing reflection...

 
Last edited:
Interesting.
I did my 21 stropped edge.
Got 9 pieces out of the medium thickness bank.
But only two from a skinny band.
I dont think I will ever do this test again. But had to atleast try it.
 
Blackie Scantling said:
My ESEE 4 didn't cut sh*t. For three nights I sat here and reprofiled the blade on my ESEE 4 to a convex grind and thought it had a sharp edge but it didn't cut the rubber band once, even after multiple tries. I hate this f*&^%$# knife. The 1095 is too thick and too hard to sharpen. At least my CS Trail Master Chinese copy cut every rubber band at least in one piece.
Click to expand...

Please get rid of all your knifes ASAP.
 
Wow, thanks. Now my wife is sure I'm crazy. My Military cut one long and one short piece.
 
I could only find one rubber band and it was one of those big gummy jobs that stretched like a foot. What a mess. I found at least a dozen pieces and I'm sure I'll find more.
Then I had to do my other favorite. Cutting the corner of a phone book. I don't know why but it just brings a big grin when the confetti flies. It's the little things I guess. On a Friday night. I need a life... :(
 
I'm going to buy some rubber band stock right now! I'd like to see the video to see why it cuts them into multiple pieces.
 
You must log in or register to reply here.
Back
Top