S-91263A577 5/16"-18 x 1 1/2" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating that protects against rust and extends service life in harsh industrial environments
• Exceptional tensile strength of 130,000 psi ensures reliable performance under heavy loads and prevents fastener failure
• Rockwell C39 hardness provides excellent wear resistance and maintains thread integrity during repeated installations
• Class 3A thread fit offers precise engagement with mating parts for secure fastening without cross-threading
• 82° countersink angle with standard flat head profile enables flush mounting for clean, professional finishes
• 3/16" hex drive allows for high-torque installation with standard tools while preventing cam-out
• Full threading along the 1-1/2" length provides maximum grip strength and adjustment flexibility

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head screws deliver critical engineering solutions where high tensile strength and corrosion resistance are paramount. The zinc-plated alloy steel construction withstands demanding industrial conditions while the coarse UNC threads provide rapid installation and superior holding power in various substrates. The 82° countersink angle ensures seamless flush mounting in machinery, structural assemblies, and equipment where protruding fasteners are unacceptable. With fully threaded design and Class 3A thread fit, these screws maintain consistent clamping force across the entire engagement length, preventing loosening from vibration - a common failure point in industrial applications. The combination of 130,000 psi tensile strength and Rockwell C39 hardness makes them ideal for heavy-duty fastening in construction, manufacturing, and automotive applications where reliability cannot be compromised.

Specification Summary & Compliance

These industrial-grade fasteners feature precise Class 3A thread fit per UNC standards with 5/16"-18 coarse threading and 1-1/2" length. Manufacturing complies with ASTM F835 specifications for mechanical properties and dimensional accuracy. The products are fully compliant with RoHS 3 (2015/863/EU) environmental directives and REACH (EC 1907/2006) regulations regarding hazardous substances, ensuring they meet the latest international safety and environmental standards for industrial use.