S-91255A051 1/2"-13 x 3" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional durability with 120,000 psi tensile strength and Rockwell C39 hardness for long-lasting performance in demanding applications
• Superior corrosion resistance from black-oxide coating that protects against rust and extends service life in harsh environments
• Precise thread engagement with Class 3A thread fit ensuring reliable, vibration-resistant fastening connections
• Easy installation and removal with 5/16" hex drive design providing secure tool grip and efficient assembly
• Versatile coarse threading (UNC 1/2"-13) that resists loosening under vibration and allows for quick installation
• Full thread coverage along the entire 3" length for maximum grip strength and load distribution
• Regulatory compliance meeting industry standards including ASME B18.3, ASTM F835, RoHS 3, and REACH

Professional Applications & Engineering Value

These black-oxide alloy steel rounded head screws deliver exceptional engineering value for industrial applications where corrosion resistance and high tensile strength are critical. The combination of Class 3A thread fit and UNC coarse spacing provides superior vibration resistance in heavy machinery, construction equipment, and manufacturing systems. The button head design offers a low-profile finish while the fully threaded configuration ensures maximum clamping force across the entire fastener length. Engineered to withstand extreme conditions, these hex drive screws maintain their integrity in environments where ordinary fasteners would fail, making them ideal for structural assemblies, industrial machinery, and equipment requiring reliable, long-term fastening solutions.

Specification Summary & Compliance

This 1/2"-13 x 3" rounded head screw features precise Class 3A thread fit with UNC coarse thread spacing, manufactured to exacting dimensional standards. The fastener complies with ASME B18.3 specifications and ASTM F835 manufacturing standards, ensuring consistent quality and performance. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) requirements, making these screws suitable for regulated industries and international markets. The black-oxide surface treatment provides additional corrosion protection while maintaining the alloy steel's inherent strength characteristics.