Spax T-Star Washer Head construction fasteners with HCR coating are intended for wood-to-wood connections in exterior structural applications when attaching treated lumber components. These fasteners are designed with a low-profile large diameter wafer head for applications requiring additional surface area under the head for superior pull-down force. Ideal for deck ledger attachment and multi-ply beam applications. Cold-rolled "carbon steel" wire heat treated to Grade 5 durability and plated with an HCR (High Corrosion Resistance) double barrier coating. "HCR" is tested and recognized for use in ground contact pressure treated lumber for exterior, freshwater general construction applications.