What is the difference between Electro-Galvanized (EZ) and Hot-Dip Galvanized (HDG) finishes?

Electro-galvanized trays are best for dry indoor environments (Class 1-2). Hot-Dip Galvanized trays are dipped in molten zinc after fabrication, providing a thicker coating (over 60–80 microns) suitable for outdoor or industrial use (Class 5-8).