S-91255A847 1/2"-20 x 3" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating that protects against rust and extends service life in demanding environments
• Superior load-bearing capability thanks to 120,000 psi tensile strength and Rockwell C39 hardness for reliable performance under high stress
• Precise thread engagement with Class 3A UNF fine threads ensuring tight, secure fits and vibration resistance in critical assemblies
• Easy installation and removal with 5/16" hex drive providing positive torque transmission and reduced tool slippage
• Full-threaded design offering maximum grip length and uniform stress distribution across the entire fastener
• Low-profile rounded button head creating a smooth finished appearance while maintaining high clamp load capacity
• Regulatory compliance assurance meeting ASME B18.3, ASTM F835 standards and environmental regulations for global manufacturing applications

Professional Applications & Engineering Value

These Black-Oxide Alloy Steel Rounded Head Screws deliver critical performance advantages for industrial applications where vibration resistance and corrosion protection are paramount. The UNF fine thread configuration with Class 3A tolerance provides superior thread engagement in precision machinery, automotive assemblies, and heavy equipment where fine thread screws prevent loosening under dynamic loads. The combination of 120,000 psi tensile strength and Rockwell C39 hardness ensures these heavy duty fasteners maintain structural integrity in high-stress applications, while the black-oxide finish offers enhanced corrosion resistance without compromising dimensional accuracy. The 5/16" hex drive and button head design facilitate installation in confined spaces while providing ample torque capability for secure fastening.

Specification Summary & Compliance

This 1/2"-20 UNF Class 3A screw features precision fine threads with tight tolerance fit for reliable performance. Manufactured to ASME B18.3 and ASTM F835 specifications, ensuring dimensional accuracy and mechanical properties. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making them suitable for global industrial applications requiring restricted substance compliance.