BRITISH STAINLESS STEEL ASSOCIATIONMaking the Most of Stainless Steel

1. Home
2. Contact
3. Members Area

Stainless Steel BSENISO 3506 Fastener Grades A1, A2, (A3), & A4 (A5)

BSENISO 3506 replaces BS6105. 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.

Microsoft Word - SSAS2.31-Fastener Grades A1,A2_A3_ & A4_A5_ to BS EN ISO 3506.pdf [82.4kb]