S-91253A717 1/2"-13 x 1 5/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, extending service life in demanding industrial environments
• Exceptional mechanical strength with 130,000 psi tensile strength and Rockwell C39 hardness for heavy-duty applications
• Precise Class 3A thread fit ensures secure fastening with minimal vibration loosening in critical assemblies
• Full threading design provides maximum grip length and uniform stress distribution across the entire fastener
• Standard 82° countersink angle allows for flush mounting in various materials without protruding head issues
• 5/16" hex drive compatibility enables high-torque installation using standard industrial tools
• Comprehensive regulatory compliance meets ASTM F835, RoHS 3, and REACH standards for global market acceptance

Professional Applications & Engineering Value

These 1/2"-13 UNC flat head screws deliver exceptional engineering value in industrial applications where vibration resistance and structural integrity are paramount. The black-oxide alloy steel construction provides superior protection against environmental degradation, while the Class 3A thread fit ensures precise engagement in machinery, structural steel frameworks, and heavy equipment assemblies. The fully threaded design with coarse UNC threading facilitates rapid installation in manufacturing lines and maintenance operations. The 82° countersink angle and flat head profile create seamless surface finishes in automotive, construction, and industrial machinery applications where aerodynamic or safety considerations require flush-mounted fasteners.

Specification Summary & Compliance

Manufactured to exacting inch system measurements with Class 3A thread fit precision and UNC coarse thread standard. These screws maintain dimensional accuracy per ASTM F835 specifications with 1/2"-13 thread size and 1-5/8" length. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets. The right-hand thread direction and standard flat head profile provide consistent performance in automated assembly systems and manual installation scenarios.