S-91255A594 5/16"-18 x 9/16" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating for extended service life in demanding industrial environments
• Exceptional tensile strength of 120,000 psi ensures reliable performance under high-stress applications
• Precision Class 3A thread fit provides superior engagement and vibration resistance in critical assemblies
• Hex drive compatibility with 3/16" tools enables secure installation and removal in confined spaces
• Full threading design allows complete fastener engagement along the entire 9/16" length
• Rounded button head profile offers a low-profile finish while maintaining high torque capability
• Comprehensive regulatory compliance including RoHS 3 and REACH for global manufacturing applications

Professional Applications & Engineering Value

These black-oxide alloy steel button head screws deliver exceptional engineering value in industrial fastening applications where vibration resistance and corrosion protection are critical. The 5/16"-18 UNC coarse thread configuration ensures rapid installation and reliable performance in materials where fine threads might strip or fail. The hex drive system provides superior torque transmission compared to other drive types, preventing cam-out during high-torque applications. Engineered with Rockwell C39 hardness and 120,000 psi tensile strength, these fasteners maintain integrity in heavy machinery, automotive assemblies, and structural applications where fatigue resistance and long-term reliability are paramount requirements.

Specification Summary & Compliance

Manufactured to precision Class 3A thread tolerances with UNC coarse thread spacing and right-hand threading. Complies with ASME B18.3 and ASTM F835 manufacturing specifications for dimensional accuracy and mechanical properties. Meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) regulations for chemical safety. Features fully threaded design with 0.313" thread diameter and 9/16" length for consistent performance across industrial applications.