S-90585A149 3/8"-16 x 4 1/2" ASME B18.3, ASTM F879 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance from 316 stainless steel and passivated finish, ideal for harsh chemical and marine environments
• Exceptional tensile strength of 70,000 psi ensures reliable performance under high-stress industrial loads
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies
• Full threading along the 4 1/2" length offers maximum grip and adjustment flexibility in deep applications
• 82° countersink angle with flat head design creates a flush, professional finish while distributing clamp load effectively
• Hex drive (7/32") compatibility allows for high-torque installation with standard industrial tools
• Compliance with ASME B18.3, RoHS 3, and REACH guarantees material safety and meets rigorous international engineering standards

Professional Applications & Engineering Value

This 316 stainless steel flat head screw is engineered to solve critical challenges in demanding environments where corrosion and mechanical stress are concerns. The combination of UNC coarse threading and Class 3A fit ensures rapid assembly with minimal cross-threading risk, while the passivated finish significantly enhances pitting and crevice corrosion resistance—making it ideal for chemical processing, marine hardware, and food-grade equipment. The fully threaded design and 82° countersink provide uniform stress distribution and a flush mounting solution, preventing snagging in machinery and conveyor systems. These features deliver long-term reliability, reduced maintenance cycles, and compliance with stringent industrial specifications for heavy-duty fastening applications.

Specification Summary & Compliance

This screw maintains precise dimensional accuracy with Class 3A thread fit per UNC standards, 82° countersink angle, and head diameter tolerance of -0.061" to 0". Manufacturing and material specifications conform to ASME B18.3 (ASTM F879), ensuring consistent performance in mechanical assemblies. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), affirming its suitability for regulated industries and environmentally conscious supply chains.