Hillman 1 2 in. x 5 1 2 in. Hot Dipped Galvanized Steel Carriage Bolts, 25 Pack Brass Plated easy install floor that looks stunning Item Weight:.625 easy install floor that looks stunning and stands up to everyday life Product Length 20 in Product Width 20 in Product Thickness 9 Specification Details Diameter 1 2 inch Length 5 1 2 inch Material Steel Finish Hot Dipped Galvanized Grade 2 Thread Type Coarse Unit of Measurement SAE Number in Package 25 pack Packaging Type Boxed Head Style Carriage (dome head with square neck) Frequently Asked Questions (FAQ): A: The dome head provides a semi flush finish and the square underside locks into wood