Add new joist hangers on top of old?- proper joist hanger nails ,14/8/2020· These nails are hot dipped and say so on the package. These nails do not say "hot dipped" and are almost certainly cold galvanized, and are substandard. Just use joist hanger nails, they are the correct strength and proper coating for treated wood and rust prevention.Simpson SUR210 Joist Hanger Skewed Right - GalvanizedSimpson Strong-Tie SUR joist hangers are skewed 45 degrees right and utilize angled nail slots to direct nails for proper installation. The Strong-Tie SUR210 skewed joist hanger features a G90 galvanized coating and requires the use of hot-dip galvanized fasteners which meet the specifications of ASTM A153. Use all specified fasteners.