Tensile strength

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Mar 26, 2000
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Don't really need exact numbers, but wonder if anyone has access to a physics lab who can measure the strength of dental floss, maybe even a couple types.

Is it the panacea for PSK's?

Instead of fishing line, or in addition to?
 
tensile strength is easy... tie a piece to something and keep on adding weights till it snaps... do it a few times and take an average...
 
Some bowstring material is over 500,000 psi. It isn't horribly expensive, $20-30 for a few hundred meters on a spool ( http://www.lancasterarchery.com/ ). Fishing line may be cheaper.

Structural steel is about 40,000-50,000 psi (1 square inch of steel fails at that many pounds) for reference.

In case anyone is as bad about forgetting formulas as me, tensile stress T in psi is

T = 1.273 * lbs / (dia^2),

where diameter is in inches, and 1.273 is 4/pi. This is just force/area.

Scott
 
tensile strength is typically force per area cross-section, hence it is typically rated as pounds force per square inch.
However following Melancholy Mutt's suggestion of just putting more weight on it till it breaks will give you a good idea of its breaking strength, which is probably all your looking for.
To actually get the tensile strength you would have to divide by the area, figuring that out for dental floss seems like too much.
Follow Mutt's advice.
 
Originally posted by beezaur


Structural steel is about 40,000-50,000 psi (1 square inch of steel fails at that many pounds) for reference.


Scott

Some silicon-alloyed steel for suspension bridges has been tested to 80,000 psi... but that doesn't come waxed and mint-flavored :D
 
Thanks all.

I will keep looking for the Spectra line. I haven't been able to find any at the local "sporting" good stores. Of course, nothin but Scioto salmon (carp) around here.

Mike
 
I wonder how tennis racquet string(either natural gut or synthetic) stacks up?
 
Try Cabela`s

They carry a boat load of the stuff in 1000 yds spools and smaller amounts.
 
Here's what insomnia and Christmas break will do: I tested some Western Family waxed, mint dental floss on my bow scale.

Four strands broke at 70 lbs, or 17.5 lbs per strand. It is hard to measure, but I got an average of about 0.010 inches diameter. Using the above formula, the breaking stress is about 220,000 psi, about the same as the prestressing steel in most concrete bridges.

So there you go - in a pinch you can use dental floss to fix a broken bridge. Just substitute 2000 strands of floss for every 1/2 inch, 7-wire prestressing strand, and you're good to go. Of course, it will stretch a little more. . .

Scott
 
Mike-
Here is a source (and a brand name to look for on the web).
http://www.wolfffishing.com/spidspec20.html
-carl

PS- The rest of the story...
Spiderwire....
Scientists doing research in advanced materials have long known that a
spider's silk is the strongest fiber in the world by a wide margin.
Ounce by ounce, it's many times stronger than steel, yet it is incredibly
soft and resilient. In fact the US government has been funding extensive
research with spiders and spider's silk for years...attempting to develope
lighter weight, bulletproof materials for the military. Well known
chemical and fiber companies such as DuPont, Dow and AlliedSignal have also
spent hundreds of millions in their attempts to develop the ultimate high
strenght fiber...a synthetic spider's silk.

Back in 1965, DuPont scientists thought they had "the" ultimate high-
strenght fiber when they introduced Kevlar, and for years it was the
strongest, manmade fiber available for high stress applicaitons like
ballistic armor.
Then, in 1985, a team of researchers at AlliedSignal Inc. upped the ante
by introducing an entirely new class of fiber called Ultra High Molecular
Weight Polyethylene. This fiber, now called Spectra easily stops High-
velocity bullets and bomb fragments. It's a full 30tronger than
Kevlar, it's more than 10 times stronger than steel, yet spectra is
virtually transparent to radar! Needless to say, spectra is quickly
finding its way into high-tech applications far too sensitive to
mention here.

The scientists a AlliedSignal applied many of the structural design
concepts behind two of nature's strongest materials...spider's silk
and diamonds...to create spectra, the world's strongest and lightest
fiber. Their patented process first realigns the carbon atoms in
high density polyethylene. Then, this super tough material is shot
through a nozzle-like device called a spinnerette under extremely high
pressures. The result...much like what happens with the spinnerettes
found on a spider...is the excretion of tiny strands or micro-filaments
of spectra. These micro-filaments look and feel like angel hair or
the silky material produced by a spider as it spins a web. Soft as
silk, with virtually zero stretch, these micro-fine "synthetic wires"
are deceptively strong- ounce for ounce they're 10 to 15 times
stronger than steel.

The performance advantages of this virtually indestructable, ultra-
thin line add a whole new dimension to the sport. In fact, spectra
has created an entirely new class of line some are now calling
"Super Lines". That's the Good news.

The bad news is this stuff is always going to be a little pricey and
very hard to get. The raw material used to make spiderwire is
extremely expensive...50 to 150 times the cost of nylon!

It's hard to get because there's only one plant in the world making
spectra and almost all of it goes for military or life-saving
applicaitons. Even when spectra fiber is available, Safariland's
exclusive micro-braiding process is slow and tedious. It takes
one machine over two days to braid just 1,000 yards of spiderwire
and then, because safariland is totally committed to quality,
they inspect every inch of line by hand.
 
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