S-91266A191 8-32 x 1/4" ASTM F835 Alloy Steel Thread-Locking Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking: Nylon patch thread locker ensures secure fastening in high-vibration environments, reducing maintenance needs.
• Exceptional tensile strength: 130,000 psi rating provides reliable performance under heavy loads and stress conditions.
• Corrosion-resistant finish: Black-oxide coating on alloy steel enhances durability and longevity in harsh industrial settings.
• Precise thread engagement: Class 3A UNC coarse threads offer superior fit and reduced risk of cross-threading during assembly.
• Wide temperature tolerance: Operates effectively from -65° to 250°F, suitable for diverse thermal environments.
• Flush mounting capability: Standard 82° countersink angle allows for smooth, recessed installation in various materials.
• Regulatory compliance assurance: Meets ASTM F835, RoHS 3, and REACH standards for quality and environmental safety.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, this black-oxide alloy steel flat head hex screw combines high tensile strength and nylon patch thread locking to address critical fastening challenges. The UNC coarse thread design with Class 3A fit ensures rapid, secure installation in metal, plastic, and composite assemblies, minimizing assembly time while preventing loosening under dynamic loads. Its fully threaded construction and 82° countersink angle provide uniform clamping force and flush surface finishes, ideal for machinery, automotive components, and electronic enclosures where vibration resistance and reliability are paramount. The temperature-resistant properties make it suitable for outdoor equipment and thermal cycling environments, delivering consistent performance without compromising structural integrity.

Specification Summary & Compliance

This screw features precise 8-32 UNC coarse threads with Class 3A tolerance for accurate fit, manufactured to ASTM F835 specifications. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring adherence to environmental and safety standards. The fully threaded design and right-hand thread direction support efficient installation in standard applications.