S-91771A582 5/16"-18 x 7/8" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction, ideal for harsh industrial environments and outdoor applications.
• Exceptional mechanical strength offering 80,000 psi tensile strength and Rockwell B80 hardness for reliable performance under high-stress conditions.
• Precision coarse threading (UNC) with Class 2A fit ensures quick assembly, reduced cross-threading risk, and secure fastening in various materials.
• Optimized flat head design with 82° countersink angle provides a flush, tamper-resistant finish that enhances safety and aesthetics.
• Efficient Phillips drive (No. 4) allows for straightforward installation with standard tools, minimizing installation time and labor costs.
• Full threading along the 7/8" length maximizes grip and load distribution, preventing loosening in dynamic or vibrating equipment.
• Comprehensive regulatory compliance including ASME B18.6.3, RoHS 3, and REACH, ensuring safety, environmental responsibility, and global acceptance.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these 5/16"-18 UNC flat head screws address critical challenges in machinery assembly, structural frameworks, and corrosion-prone applications. The passivated 18-8 stainless steel material delivers excellent resistance to oxidation and chemical exposure, prolonging service life in marine, chemical processing, and food-grade environments. The coarse thread design and Class 2A thread fit facilitate rapid installation in soft metals or plastics, reducing assembly errors and maintenance downtime. With an 82° countersink angle and flat head profile, these screws provide a seamless finish that minimizes protrusion risks in conveyor systems, enclosures, and automotive components, ensuring both operational safety and compliance with ASME B18.6.3 standards.

Specification Summary & Compliance

This fastener adheres to Class 2A thread fit tolerances per UNC standards, with precise dimensions including a 7/8" length and 5/16"-18 coarse thread. Manufacturing follows ASME B18.6.3 specifications for consistency and reliability. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing the absence of hazardous substances and supporting sustainable procurement practices.