Constructed from the finest aerospace-quality materials, these hex nuts are available in most sizes to meet your needs. All hex nuts meet ARP’s exacting quality control standards and are black oxided. All hex nuts are rated 180,000 psi tensile strength. PartNumber : arp200-8602 Description : Standard Hex Nut; Single Piece Socket : 1/2 Size : 5/16-24 Engine Components::Hardware Kits - Other