S-90585A677 5/16"-24 x 1/2" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 316 stainless steel construction and passivated finish, ideal for harsh chemical and marine environments
• Precise thread engagement with Class 3A fit and UNF fine spacing for superior vibration resistance and reliable fastening
• High-strength performance delivering 70,000 psi tensile strength and Rockwell B55 hardness for demanding industrial applications
• Optimized flush mounting with standard 82° countersink angle and flat head design for seamless surface integration
• Secure hex drive installation using 3/16" drive for positive torque transfer and reduced cam-out risk
• Full thread coverage along the 1/2" length for maximum grip strength and load distribution
• Regulatory compliance assurance meeting ASME B18.3 standards, RoHS 3, and REACH for global quality acceptance

Professional Applications & Engineering Value

These 316 stainless steel flat head screws address critical engineering challenges in corrosive and high-stress environments. The combination of UNF fine threading with Class 3A fit provides exceptional resistance to vibration loosening, making them ideal for machinery, marine equipment, and chemical processing applications where reliability is paramount. The passivated finish enhances the natural corrosion resistance of 316 stainless steel, extending service life in saltwater, chemical exposure, and outdoor conditions. The 82° countersink and flat head profile ensure flush mounting in precision assemblies, while the hex drive facilitates secure installation in confined spaces. These fully threaded screws deliver consistent clamping force across the entire engagement length, preventing joint failure in structural applications.

Specification Summary & Compliance

Manufactured to ASME B18.3 specifications with Class 3A thread fit ensuring precise dimensional accuracy. Thread configuration follows 5/16"-24 UNF standards with fine spacing. Material certification includes 316 stainless steel with Rockwell B55 hardness and 70,000 psi tensile strength. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations for environmental safety. Head diameter tolerance maintained at -0.056" to 0" for consistent seating in countersunk applications.