OK, so aluminum might last for millions of cycles of vibration. If my element is humming at 30 Hz, it will load and unload: 30 times a second 1800 times a minute 108,000 times an hour 2.592 million times a day 18.144 million times a week You get the idea. I think using rope is safer than letting it hum. 73, Tom W8JI W8JI@contesting.com