Technical specifications and performance indicators for screws according to ASTM F879
The ASTM F879 standard sets strict requirements for the chemical composition and mechanical properties of corrosion-resistant metric fasteners. The nomenclature includes socket head cap screws and flat countersunk head screws. The nominal thread diameter range is from M3 to M20. EV Group China products comply with these specifications, ensuring high reliability of connections in corrosive environments.
Classification of strength characteristics according to the standard:
- Class A1-50: austenitic steel in the annealed condition, tensile strength up to 585 MPa.
- Class A1-55: austenitic steel after cold working, minimum tensile strength 550 MPa.
- Class A1-70: austenitic steel after cold working, minimum tensile strength 700 MPa.
The EV Group China engineering department recommends selecting the strength class based on the calculated loads on the assembly and operating conditions. These fasteners are optimal for industrial equipment operating under exposure to moisture and chemically active substances.