LePage's Metal Epoxy J-B Weld Faststeel Epoxy Putty if you have gaps to fill
LePage's Press-Tite Contact (solvent-based) LePage's Press-Tite Green Contact Cement 3M Fastbond 30-NF
Whenever you are gluing metal it's a good idea to clean it first with steel wool or sandpaper. (Rust never sleeps.)