S-91253A115 4-40 x 1" 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.
• Precise Class 3A thread fit provides superior engagement and vibration resistance, minimizing loosening and maintaining assembly integrity over time.
• Black-oxide finish on alloy steel offers enhanced corrosion resistance and a durable, non-reflective surface suitable for industrial environments.
• 82° countersink angle and flat head design allow for flush mounting, creating a smooth surface finish and preventing snagging in assembled components.
• Hex drive (1/16") enables secure tool engagement and efficient installation, even in confined spaces, improving assembly speed and reliability.
• Full threading and coarse UNC spacing facilitate quick installation and strong holding power, ideal for a wide range of materials and applications.
• Compliance with ASME B18.3, ASTM F835, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations, providing peace of mind for global sourcing.

Professional Applications & Engineering Value

This 4-40 UNC flat head screw is engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in harsh environments. The black-oxide alloy steel construction, combined with a Rockwell C39 hardness, delivers durability and resistance to wear, making it suitable for machinery, electronics, and automotive assemblies. The fully threaded design with coarse spacing ensures rapid installation and robust clamping force, while the 82° countersink provides a seamless fit in pre-drilled holes. Ideal for applications requiring high tensile strength and compliance with rigorous standards, this screw minimizes maintenance needs and enhances long-term reliability in industrial screw fastening systems.

Specification Summary & Compliance

This product features a Class 3A thread fit per UNC standards, ensuring tight tolerances for precision assembly. It meets ASME B18.3 and ASTM F835 specifications for dimensional accuracy and performance. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming adherence to environmental and safety regulations for industrial use.