I just put a file test to a piece of TI tubing in my desk. It filed like
butter, much like aluminum. I don't know what it's ability to be hardened
is. Perhaps it age/work hardens like aluminum or can be heat treated.
Think I will stick with high quality HT alloy steel locks. Need to learn
more about TI.

Ken


"Mark Hickey" wrote in message
...
David Kerber wrote:

Ti is stronger than steel by unit weight, but not by unit volume, so for
the same tensile strength, it would be about the same diameter, but
lighter. Ti, however, is also not particularly hard, which makes it
vulnerable to hacksaws. Steel, OTOH, can be made case-hardened, which
makes the outside resistant to hacksaws while keeping the inside
malleable so the chain as a whole doesn't get brittle. Ti might be good
as a towchain, though ggg - nice and light.

Actually, ti has a couple characteristics that might actually make it
a good choice for a bike lock. It can be a bear to cut through - it
tends to "smear" when cutting, though I don't know how much of an
impediment that would be to a hacksaw. The only ti I've ever
hacksawed through was a skewer, and I do remember being amazed at how
long it took (had it been steel, it would have been MUCH faster).

Depending on the alloy, it's capable of quite a bit of elongation
before it ruptures - that might make it more difficult to use a bottle
jack to "pop" a U-lock. But the ultimate strength would still be less
on a volume basis than hi-tensile steel, so it CAN break.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame