S-91263A508 6-40 x 1/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with zinc-plated alloy steel construction for extended service life in demanding environments
• Superior holding power with 130,000 psi tensile strength and Rockwell C39 hardness for reliable, vibration-resistant connections
• Precise thread engagement with Class 3A fine UNF threads ensuring tight, secure fits and reduced loosening risks
• Efficient installation with 5/64" hex drive and standard 82° countersink angle for flush mounting and quick assembly
• Full-threaded design providing maximum grip length and uniform stress distribution across the entire fastener
• Regulatory compliance meeting ASTM F835 specifications and environmental standards including RoHS 3 and REACH
• Versatile right-hand threading compatible with standard UNF nuts and components for broad application compatibility

Professional Applications & Engineering Value

These 6-40 UNF flat head screws deliver critical performance advantages for industrial applications where vibration resistance and corrosion protection are paramount. The zinc-plated alloy steel construction provides excellent durability against environmental factors, while the Class 3A thread fit ensures precise tolerances for secure fastening in machinery, equipment assemblies, and precision instruments. The fine UNF threading offers superior resistance to loosening under dynamic loads, making these fully threaded screws ideal for applications requiring consistent clamping force. The 82° countersink angle allows for flush mounting in predrilled holes, creating clean, professional finishes while maintaining structural integrity. These high-strength fasteners are engineered to withstand rigorous industrial conditions while maintaining compliance with critical industry standards.

Specification Summary & Compliance

These inch-system fasteners feature Class 3A thread fit with UNF fine threading (6-40) and precise dimensional tolerances. Manufacturing complies with ASTM F835 specifications for mechanical properties and performance standards. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring restricted substance compliance for international markets. The combination of 130,000 psi tensile strength and Rockwell C39 hardness provides reliable mechanical performance for demanding industrial applications.