5/16" x 6" (50 Pack) Galvanized Lag Pack Grade A - Hot Dip Galvanized for Exterior Use - by, LLC$$Hardware

Superior Corrosion Resistance External Hex Drive ASTM A307 Compliant Hot Dipped GalvanizedYou may also like 3/8"-16 X 2" Zinc Plated Threaded Rod Studs (Box of 100).