The 3/8 x .063 NAS1149 Military Flat Washer is a thin, flat ring made of 18-8 stainless steel. It is designed to be used with bolts and screws to distribute the load and prevent damage to the surface of the material being fastened. The washer has an outer diameter of 3/8 inches and an inner diameter of .063 inches. It is manufactured in accordance with the National Aerospace Standard (NAS) 1149 and meets the requirements of the Defense Federal Acquisition Regulation (DFAR). The washer is corrosion-resistant and has a bright finish.