curt> I assume because its such a soft metal. I wonder what the max curt> load/heat threshold on 12guage Aluminum vs Copper would be Rule of thumb is that you need the next step up in wire size (2 gauge numbers down) compared to copper for the same current rating. Aluminum is used because it's cheaper than copper for a given current rating. Also (in overhead lines) because it's lighter. If carefully installed with correct devices, it's supposed to be fine. If it's just a run from the transformer to the main breaker, that isn't too tough a requirement, and in any case the splices are in a steel box. The trouble starts when you run it all over the house, and have the job done by an incompetent bum with a license. paul

Someone wrote...(re: AL wiring) Someone else replied... They were thinking about WW2, that's when people switched to AL as copper was scarce on the home front. At least that's what I recall being told. Plus I know there was a time back when our house was originally built that copper was astronomically expensive (I think pennies changed to clad then?) and that may also have been a driving factor. About half the wiring in my house is AL, the rest copper. As long as you use the switches & outlets made for AL, and every few years undo them all, rough up the ends, apply the special AL goo stuff, and tighten them back down it IS safe. However, it's a royal PAIN to maintain the way it's supposed to be. Jay