This hex nut meets DIN 934 standards and is made from A8 stainless steel (1.4529) with metric threading. It's a super austenitic stainless steel—also known as HCR (High Corrosion Resistant)—that protects against chloride stress corrosion as well as localized issues like pitting and crevice corrosion. Material 1.4529 is rated in the highest corrosion class, CRC V (very high, EN 1993-1-4), for components and fasteners. That makes 1.4529 fasteners an excellent choice for demanding applications such as swimming pools and tunnels.