F436 Washers are for use in structural applications such as buildings, bridges and highway construction. They are made from domestic medium carbon steel. Heat treated to R/C 38-45 and marked with "F436" Complete domestic certs with the material statement "Melted and Manufactured in the USA" Heat Treat and Plating certifications are provided. Stocked in sizes 1/2" through 2" in Plain, Mechanical or Hot Dip Galvanize finish.