S-91355A086 5/16"-18 x 3/4" ASME B18.3, ASTM F835 Steel Flanged Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional durability and corrosion resistance thanks to the black-oxide finish on alloy steel, extending service life in harsh industrial environments.
• Superior load-bearing capacity with a high tensile strength of 120,000 psi and Rockwell C39 hardness, ensuring reliable performance under heavy stress.
• Precise and secure fastening achieved through Class 3A thread fit and UNC coarse threading, reducing the risk of cross-threading and loosening.
• Efficient installation and removal with a hex drive design, allowing for high torque application and easy access in confined spaces.
• Enhanced stability and distribution of clamp load provided by the wide button head and integrated flange, minimizing surface damage.
• Full compliance with industry standards including ASME B18.3 and ASTM F835, guaranteeing consistent quality and interoperability.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance, ensuring safety and regulatory adherence for global supply chains.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Rounded Head Screw is engineered to address critical challenges in heavy-duty assembly, such as vibration resistance and long-term reliability. The UNC coarse thread with Class 3A fit ensures quick installation and robust holding power in materials like metal and hardened plastics, reducing assembly time and maintenance needs. The hex drive and flanged button head design provide a flush finish and even pressure distribution, ideal for machinery, automotive frames, and structural applications where space is limited and high tensile strength is non-negotiable. Its black-oxide coating adds a layer of corrosion protection, making it suitable for both indoor and outdoor industrial environments without compromising on mechanical performance.

Specification Summary & Compliance

This screw features a 5/16"-18 UNC coarse thread with Class 3A thread fit for precise tolerances, fully threaded for consistent engagement. It meets ASME B18.3 and ASTM F835 specifications, ensuring dimensional accuracy and performance reliability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting safe and sustainable use in global industrial markets.