Down Under wire (Australian wire) becomes harder as it is bent, so heat treating is not necessary. Available in Spools of 25 feet.
Peter says...
"Did you love Wilcox wire? I sure did. Cheap, versatile, great for spans, and it actually did open bites and change arch forms. The only problem was my patients didn't like its dark colour. Well here it is without the dark colour, just like the one from Whittlesea."