For aircraft grade stainless steel safety wire, try AircraftSpruce.com. The wire is used to wire on critical bolts, fittings, etc. to ensure they can't twist off in flight. Even the oil filter is wired on. That's why aircraft engines are so expensive to maintain. What take minutes to do on an automobile engine takes 1/4 hours on an airplane.

http://www.aircraftspruce.com/catalog/appages/safetywire.php