S-90585A825 5/8"-11 x 1 1/4" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh chemical and marine environments.
• Exceptional holding power from fully threaded UNC coarse spacing and Class 3A thread fit, ensuring reliable fastening in high-vibration applications.
• Enhanced durability with a tensile strength of 70,000 psi and Rockwell B55 hardness, providing long-term performance under heavy loads.
• Optimized flush mounting thanks to the standard flat head profile and 82° countersink angle, creating a smooth, secure surface finish.
• Easy and secure installation with a 3/8" hex drive, allowing for high torque application without slippage.
• Extended service life due to the passivated finish, which adds an extra layer of protection against oxidation and wear.
• Guaranteed reliability and interchangeability as it meets ASME B18.3 specifications, RoHS 3, and REACH regulations.

Professional Applications & Engineering Value

This 316 stainless steel flat head screw is engineered to address critical challenges in demanding industrial settings. Its UNC coarse thread and Class 3A fit provide rapid assembly and superior resistance to loosening in high-vibration machinery, structural frameworks, and heavy equipment. The passivated finish significantly enhances the innate corrosion resistance of 316 stainless steel, making it a top choice for applications exposed to chemicals, saltwater, or outdoor elements. The combination of 70,000 psi tensile strength and a fully threaded design ensures maximum clamp load and pull-out strength, solving the problem of joint failure in critical assemblies. Its 82° countersink and flat head design are perfect for applications requiring a flush, aerodynamic, or safe surface, commonly used in metal fabrication, transportation, and processing equipment.

Specification Summary & Compliance

This screw features a 5/8"-11 UNC thread with a Class 3A thread fit for precision and strength. The dimensional accuracy, including head diameter and 82° countersink angle, conforms to the ASME B18.3 standard. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and suitable for global industrial supply chains.