S-91253A119 4-40 x 1 1/2" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with Black-Oxide coating, ideal for harsh industrial environments.
• High tensile strength of 130,000 psi ensures reliable performance under heavy loads and vibrations.
• Precise Class 3A thread fit guarantees secure, tight fastening with minimal risk of loosening.
• 82° countersink angle allows for a flush, professional finish in countersunk applications.
• Partially threaded design provides optimal grip and clamping force where full threading isn't required.
• Hex drive (1/16") enables easy installation and removal with standard tools, reducing assembly time.
• Compliance with ASTM F835, RoHS 3, and REACH ensures safety, environmental responsibility, and industry acceptance.

Professional Applications & Engineering Value

These 4-40 UNC flat head screws are engineered from Black-Oxide Alloy Steel to address critical industrial challenges, such as corrosion and mechanical stress. The coarse thread spacing and Class 3A thread fit provide superior holding power in materials like metal and plastic, reducing the risk of strip-out in high-vibration settings. With a Rockwell C39 hardness and 130,000 psi tensile strength, they excel in demanding applications—from machinery assembly to electronic enclosures—where durability and reliable fastening are paramount. The 82° countersink angle ensures a smooth, flush finish, enhancing both safety and aesthetics in finished products.

Specification Summary & Compliance

This product adheres to Class 3A thread fit for precision and meets ASTM F835 specifications for mechanical properties. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring it is free from hazardous substances. The screw features UNC coarse threads, a right-hand thread direction, and partial threading up to a minimum of 1", providing consistent performance in industrial fastening applications.