S-90585A563 1/4"-28 x 5/8" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance from 316 stainless steel with passivated finish, ideal for harsh environments and chemical exposure
• Superior mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for reliable load-bearing performance
• Precise thread engagement with Class 3A fit and UNF fine threads ensuring vibration resistance and secure fastening
• Streamlined flush installation with standard 82° flat head profile for smooth surfaces and reduced snagging risks
• High-torque installation capability through 5/32" hex drive for efficient assembly with standard tools
• Full regulatory compliance meeting ASME B18.3 specifications and environmental standards including RoHS 3 and REACH
• Complete threading coverage along the 5/8" length for maximum grip strength in various material thicknesses

Professional Applications & Engineering Value

This 316 stainless steel flat head screw delivers critical performance advantages in demanding industrial settings where corrosion resistance and mechanical reliability are paramount. The combination of UNF fine threading with Class 3A fit provides exceptional vibration resistance in machinery, automotive, and marine applications, while the passivated finish enhances protection against chemical degradation and saltwater exposure. The 82° countersink angle ensures seamless flush mounting in precision equipment, reducing aerodynamic drag and preventing material snagging. Engineered to ASME B18.3 standards, these hex drive screws offer consistent quality for OEM manufacturing and maintenance operations where fastener integrity directly impacts system safety and longevity.

Specification Summary & Compliance

Manufactured to precise dimensional tolerances with Class 3A thread fit per UNF specifications, ensuring consistent threading performance. The 5/8" length and 0.531" head diameter maintain strict adherence to ASME B18.3 manufacturing standards. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations guarantees safe use across regulated industries. The 82° flat head profile and fully threaded construction provide standardized installation across compatible applications.