S-91253A591 5/16"-18 x 2" 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
• Precision thread engagement with Class 3A fit ensuring reliable, vibration-resistant connections
• Optimized drive efficiency with hex drive design providing superior torque transmission and installation control
• Versatile partial threading allowing precise clamping force distribution across connected components
• Industry-standard compliance meeting ASME B18.3 and ASTM F835 specifications for guaranteed performance
• Environmental responsibility with RoHS 3 and REACH compliance for sustainable manufacturing operations

Professional Applications & Engineering Value

These black-oxide alloy steel flat head screws deliver critical performance advantages in industrial fastening applications where strength, corrosion resistance, and precision matter most. The 5/16"-18 UNC coarse thread configuration ensures rapid installation and superior holding power in metal assemblies, machinery, and structural components. The partially threaded design concentrates clamping force precisely where needed, preventing joint loosening under vibration while the 82° countersink angle provides flush mounting in precision-machined surfaces. Engineered for heavy-duty industrial applications, these screws maintain integrity under extreme mechanical stress thanks to their high tensile strength and hardened alloy steel construction, making them ideal for manufacturing equipment, automotive assemblies, and construction machinery where reliability is non-negotiable.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit for superior dimensional accuracy and consistent performance. These flat head screws comply with ASME B18.3 and ASTM F835 specifications, ensuring interchangeability and reliability across industrial applications. The product meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance requirements, demonstrating commitment to sustainable manufacturing practices while delivering uncompromised mechanical performance for professional users.