S-91263A560 1/4"-20 x 7/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 PSI ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Zinc-plated alloy steel construction provides superior corrosion resistance, extending service life in harsh industrial environments.
• Class 3A thread fit offers tighter tolerances for precise, secure mating with nuts and tapped holes, minimizing backlash and improving assembly integrity.
• UNC coarse threading enables faster installation and reduced cross-threading risks, saving valuable assembly time in production lines.
• 82° countersink angle with standard flat head profile allows for flush mounting, creating a smooth surface finish and preventing snagging in machinery.
• Hex drive (5/32") design delivers high torque transmission and slip-resistant engagement, facilitating efficient installation with standard tools.
• Full threading along the 7/8" length provides maximum grip and adjustability across the entire fastener, enhancing load distribution in various materials.

Professional Applications & Engineering Value

Engineered for industrial applications requiring robust fastening solutions, this zinc-plated alloy steel flat head screw addresses common challenges like vibration loosening and environmental degradation. The Rockwell C39 hardness and 130,000 PSI tensile strength ensure it withstands heavy loads and dynamic stresses in machinery, automotive assemblies, and structural frameworks. Its UNC coarse thread and Class 3A fit provide secure, repeatable fastening with minimal risk of stripping, while the 82° countersink angle enables seamless integration into metal and composite materials. Ideal for use in high-tensile strength environments, this screw reduces maintenance needs and enhances operational safety by maintaining clamp force under extreme conditions.

Specification Summary & Compliance

This screw adheres to Class 3A thread fit for precise dimensional accuracy and UNC coarse thread standards. Manufacturing complies with ASTM F835 specifications, ensuring consistent quality and performance. It is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, meeting environmental and safety regulations for industrial use.