Alloy A320 L7 L7M Washers specially engineered for LOW temperature performance
ASTM specifications recommend a minimum Charpy impact value for ASTM A320 L7 Stud Bolts to be 20-ft-lbf @ -150F. The Charpy impact test determines the total amount of energy that is absorbed by a material during fracture, thereby indicating the material¡¯s notch toughness.
Inside ASTM A320 several grades are covered, including both ferritic and austenitic steels designated L7, B8, etc. Selection will depend on design, service conditions, mechanical properties, and low-temperature characteristics. The class D of the Astm A320 Grade L7 Material has 895MPa minimum tensile strength and 725MPa minimum yield strength. The material is made up of carbon, manganese, phosphorus, sulfur, silicon, 24% nickel, 13% chromium, molybdenum, titanium, aluminum, vanadium and boron. The ASTM A320 Grade L7m Bolts range in thread diameters from M6 through M36.