S-91253A122 5-40 x 1/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional durability with Black-Oxide Alloy Steel construction providing superior corrosion resistance and long-term reliability in harsh industrial environments.
• High tensile strength of 130,000 psi ensures secure, vibration-resistant fastening for critical assemblies without failure under stress.
• Precision Class 3A thread fit guarantees consistent, tight engagement with mating parts, reducing the risk of loosening and improving assembly accuracy.
• Undercut flat head profile with 82° countersink angle allows for flush mounting, minimizing protrusion and enhancing aesthetic finish in visible applications.
• Fully threaded design maximizes grip length and load distribution, ideal for thin materials and high-stress points.
• Hex drive (5/64") compatibility enables easy installation with standard tools, speeding up assembly and reducing labor time.
• Compliance with ASTM F835, RoHS 3, and REACH ensures adherence to strict quality and environmental standards, suitable for global supply chains.

Professional Applications & Engineering Value

These 5-40 UNC flat head screws are engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in demanding settings. Made from black-oxide alloy steel, they offer enhanced wear resistance and durability, making them ideal for machinery, electronics, and automotive assemblies where reliability is critical. The coarse UNC threads and Class 3A fit provide quick, secure fastening in materials like metal and plastic, reducing installation errors. The undercut head profile ensures a smooth, flush finish, preventing snagging and improving safety. By combining high tensile strength with environmental compliance, these screws deliver long-term performance in applications ranging from precision instruments to heavy-duty equipment.

Specification Summary & Compliance

This product features precise dimensions, including a 1/8" length and Class 3A thread fit per UNC standards, ensuring tight tolerances for reliable mating. It meets ASTM F835 specifications for mechanical properties and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free from hazardous substances and suitable for international markets.