S-91253A582 5/16"-18 x 7/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, ideal for harsh industrial environments
• Exceptional tensile strength of 130,000 psi ensures reliable performance under heavy loads
• Precise Class 3A thread fit provides secure, vibration-resistant fastening in critical applications
• 82° countersink angle enables flush mounting for clean, professional finishes
• Hex drive design allows for high-torque installation with standard tools
• Full threading along the 7/8" length maximizes grip and load distribution
• Comprehensive compliance with ASTM F835, RoHS 3, and REACH ensures material safety and reliability

Professional Applications & Engineering Value

These black-oxide alloy steel flat head screws with 5/16"-18 UNC coarse threading are engineered to solve critical fastening challenges in demanding industrial settings. The combination of Rockwell C39 hardness and 130,000 psi tensile strength provides exceptional resistance to shear forces and vibration loosening, making them ideal for heavy machinery, structural assemblies, and automotive applications. The 82° countersink angle and flat head profile ensure seamless surface integration while the hex drive system facilitates quick installation in confined spaces. These fully threaded screws maintain consistent clamping force across the entire 7/8" length, preventing joint failure in high-stress environments where reliability is paramount.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit and UNC coarse thread spacing for superior engagement. The black-oxide alloy steel construction meets ASTM F835 specifications for mechanical properties and dimensional accuracy. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets. Right-hand threaded with standard 3/16" hex drive for universal tool compatibility.