Rubber Band Sharpness Test

[Paani]

I saw this on rec.knives and thought it sounded fun, I tried it on some of my Spydercos, and indeed, it is <img src="wink.gif" width=15 height=15 align=middle>



Take a rubberband and put it around the blade and stretch the band against the spine of the knife, away from the blade. Release! The band, NOT the knife <img src="smile.gif" width=15 height=15 align=middle>



A dull blade will do nothing, or just knick the band.



A moderately sharp blade will cut the band open.



A sharp knife, like my 440V Military <img src="smile.gif" width=15 height=15 align=middle> will cut the band into SEVERAL pieces, 7 to be precise!



I've got a Moki Umi fixed blade that holds the "Vorpal Blade Record" right now, 10 PIECES!



I'm sure that factors other than sharpness are important too, but it's a FUN test <img src="smile.gif" width=15 height=15 align=middle>



I'm off to go buy more rubberbands...

[john row]

LOL
Let me know where you get the best price on rubber bands! The paper boy looks at me funny at 4 am! <img src="smile.gif" width=15 height=15 align=middle>
John Row

From Golden, Colorado and the knife cuts HAVE caught up to the paper cuts :)

[sam the man..]

Wow! <img src="smile.gif" width=15 height=15 align=middle> This is awesome! I'll be running out of rubber bands...

Sam

have spydies
will travel...

[James Mattis]

A Spyderco 6" serrated kitchen utility knife and a fairly heavy duty rubber band scored nine pieces that I could find, plus three more cuts more than halfway through the rubber band that didn't quite sever it. I think the Hattori Santoku, a rather more expensive knife, almost equalled that, if I could have found all the pieces.

:D


- JKM
www.chaicutlery.com
Good tools to sustain life, or at least make life more convenient

[Paani]

I LOVE the Hattori kitchen knives I got from you, talk about sharp! My record holding Moki came in that same shipment <img src="smile.gif" width=15 height=15 align=middle>

[James Mattis]

I did the rubber band test on a Moki Nami - the Umi's slightly shorter cousin. Twelve separate pieces, if I found them all, and six other cuts more than halfway through. Vorpal. <img src="smile.gif" width=15 height=15 align=middle>

Found another piece <img src="smile.gif" width=15 height=15 align=middle> <img src="smile.gif" width=15 height=15 align=middle>

And, finding that Moki-made knives seem to explode rubber bands with authority, I tried it on a Spyderco Calypso C54P. Here's the URL for the results.

http://www.chaicutlery.com/spyderco/Cal ... ndTest.jpg

Yep. It's sharp.

- JKM
www.chaicutlery.com
Good tools to sustain life, or at least make life more convenient



Edited by - James Mattis on 8/30/00 7:42:35 PM

[James Mattis]

And I get between six and a dozen pieces off a $10 Frosts of Sweden Model 840 carbon steel "Mora knife".


- JKM
www.chaicutlery.com
Good tools to sustain life, or at least make life more convenient

[Onehandclapping]

I'm confused -- I have more knives than I can count, most so sharp they scare people. I hook a rubber band over the back of the blade, strech it out and let it go. It gets cut. Help me with this -- how does it get cut so many times with just one "energy input" from the rubber being streched? I want to do this correctly. Looks like fun.

[Paani]

Oh oh, now you've done it,

Someone is now going to have to come up with a new field of science in RUBBERBAND PHYSICS to explain this strange new phenomenon <img src="wink.gif" width=15 height=15 align=middle>

By looking at some of the leftover exploded frangments I have here, I submit two of my current hypotheses,

A sharp knife might knick at the sides of the bands at they fly by, before cutting the band at the rear. If the nicks in the side go deep enough, the band is severed producing pieces galore <img src="smile.gif" width=15 height=15 align=middle>

There is a good example of this in James' scan where you can see how the blade sort of whittled through the band for awhile.

OR

The rubberband bunches up before impalement upon the blade, also producing pieces galore and similar effects to the abovu pic <img src="smile.gif" width=15 height=15 align=middle>


Either Way:
The knife has to be "Out of the box Spyderco" SCARY sharp to nick the band and produce pieces.

Edited by - Paani on 9/2/00 4:54:51 PM

[James Mattis]

http://www.chaicutlery.com/mora/Eriksson1-Vorpal.jpg

Eriksson #1 - a $10 knife (probably $5 in a store in Sweden), mystery carbon steel, as-issued edge. Not quite in the same class as the Calypso Jr. or the Moki fixed blades for rubber band shredding, but very respectable nonetheless.

<img src="smile.gif" width=15 height=15 align=middle>


- JKM
www.chaicutlery.com
Good tools to sustain life, or at least make life more convenient

[kraziekurtis]

This is a fun thing to do! I have scored 8 pieces with an Endura serrated!

[Rookie]

What kind of rubber bands do you have? I can only get 3 chunks of rubber band with my SHARP rookie.

In the land of knives, Spyderco is king.

[kraziekurtis]

I use industrial strength rubber bands the size of bicycle tires...the kind they use in mailrooms <img src="tongue.gif" width=15 height=15 align=middle>

Seriously though I use Office Max brand <img src="smile.gif" width=15 height=15 align=middle>