Bolts and Screws, Steel, Corrosion Resistant, UNS S17400 Tensile Strength 140 Ksi Procurement Specification
This specification covers bolts and screws made from a corrosion and heat resistant, martensitic iron base alloy of the type identified under the Unified Numbering System as UNS S17400. The following specification designations and their properties are covered: AS7474 140 ksi minimum ultimate tensile strength at room temperature 100 ksi stress corrosion test 72 ksi to 7.2 ksi tension-tension fatigue; AS7474-1 140 ksi minimum ultimate tensile strength at room temperature 100 ksi stress corrosion test 88 ksi minimum ultimate shear strength at room temperature.
Primarily for aerospace propulsion system applications where corrosion resistance and high strength in tension is required in temperatures not to exceed 600 °F.
Rationale: To revise paragraph 3.6 by adding “two to” three threads in agreement with NASM1312 test methodology and general updating of specifications and SAE formatting requirements also tables 1 to 7 have been redrawn.