S-91255A588 5/16"-18 x 2" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance in high-stress industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish extends service life in harsh environments, minimizing maintenance and replacement costs.
• Precision Class 3A thread fit provides secure, vibration-resistant connections, enhancing assembly integrity and safety.
• Fully threaded UNC coarse spacing allows for faster installation and stronger holding power in a wide range of materials.
• Hex drive design offers easy installation and removal with standard tools, improving workflow efficiency on the production line.
• High hardness (Rockwell C39) resists wear and deformation, ensuring long-term durability under repetitive loads.
• Compliance with ASME B18.3 and ASTM F835 guarantees consistent quality and interoperability in regulated industrial settings.

Professional Applications & Engineering Value

This 5/16"-18 x 2" Black-Oxide Alloy Steel Rounded Head Hex Screw is engineered to address critical challenges in heavy machinery, automotive, and construction assemblies. The alloy steel construction combined with a black-oxide surface treatment provides excellent resistance to oxidation and abrasion, making it ideal for outdoor or humid conditions where corrosion can compromise structural integrity. Its fully threaded UNC coarse spacing ensures rapid engagement and high clamp load, reducing installation time while maintaining joint security under dynamic stresses. The rounded head design and hex drive facilitate easy access in confined spaces, streamlining maintenance and repair operations. By meeting rigorous standards like ASME B18.3, this screw delivers predictable performance, minimizing downtime and enhancing the reliability of industrial equipment.

Specification Summary & Compliance

This fastener features precise Class 3A thread fit with UNC coarse threads for optimal engagement and strength. It adheres to ASME B18.3 and ASTM F835 specifications, ensuring dimensional accuracy and manufacturing consistency. Additionally, it is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe usage in global markets.