Here's what you need:
http://www.onesteel.com/productspecs.asp?specID=3087
I've got one section of sub floor held up with it because it was too high for brick piers. Bearers and joists are all Hyspan LVL. The verandahs and decks are all framed with Duragal. The guy up the hill from me has the whole subfloor made from Duragal, including bearers and joists. No problems thus far. We welded ours but the guy up the hill has tek screwed everything according to the Onesteel guidelines.
One thing that you need to be aware of, they don't recommend Duragal within a couple of kms of the coast, so if you're on the beach, it's no good for you.