BS EN ISO 3506 replaces BS 6105. Part 1 covers bolts, screw and studs, part 2 nuts and part 4 tapping screws. The chemical compositions are common to the various parts. Austenitic grades A1, A2 and A4 are shown and compared to bar grades 303, 304, 349S17, 316 and 394S17. Mechanical properties for property class 50, 70 and 80 austenitic bolts and studs and property class 20H, 25H, 30H and 40H tapping screws are tabulated and the fastener designations, such as A2-70 and A4-25H described. Duplex FA, (ferritic-austenitic similar to 1.4462, (2205), of EN 10088-1), is a likely future grade for inclusion in the standard. Fastener grade selection is covered in annexes to the standards. The standards lists grades 1.4439, 1.4539, (904L), 1.4529, (6% molybdenum austenitic), and 1.4462, (2205), as suitable for reducing the risk of chloride induced stress corrosion cracking failures in applications such as indoor swimming pools.