S-91255A595 5/16"-18 x 1 1/8" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional Durability: Made from Black-Oxide Alloy Steel with Rockwell C39 hardness, offering superior resistance to wear and corrosion in harsh industrial environments.
• High Tensile Strength: With a tensile strength of 120,000 psi, this screw ensures reliable, long-lasting fastening under heavy loads and vibrations.
• Precise Thread Fit: Class 3A UNC coarse thread spacing provides a tight, secure fit, reducing the risk of loosening and improving assembly efficiency.
• Easy Installation: The 3/16" hex drive and rounded button head design allow for quick, tool-friendly installation without compromising on grip or aesthetics.
• Full Threading for Maximum Hold: Fully threaded design ensures consistent engagement along the entire length, enhancing grip strength in various materials.
• Compliance with Industry Standards: Meets ASME B18.3 and ASTM F835 specifications, guaranteeing quality and interoperability in professional applications.
• Environmental and Safety Compliance: RoHS 3 and REACH compliant, ensuring safe use in regulated industries without harmful substances.

Professional Applications & Engineering Value

This 5/16"-18 UNC Class 3A Black-Oxide Alloy Steel Rounded Head Hex Screw is engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in demanding settings. The Black-Oxide coating on the alloy steel base provides enhanced corrosion resistance, extending service life in environments like machinery assembly, automotive systems, and construction frameworks. Its coarse UNC threading and Class 3A fit deliver superior thread engagement, minimizing the risk of strip-out and ensuring stable connections in high-stress applications. The rounded button head and hex drive facilitate easy access in confined spaces, making it ideal for repetitive installations in manufacturing lines or maintenance operations. By combining high tensile strength with full threading, this screw offers reliable performance in heavy-duty fastening, reducing downtime and maintenance costs for B2B clients.

Specification Summary & Compliance

This product features precise dimensions, including a 1 1/8" length and Class 3A thread fit with UNC coarse spacing, ensuring accurate and consistent fastening. It complies with ASME B18.3 and ASTM F835 standards for dimensional and mechanical integrity, and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations for environmental safety and restricted substance control.