S-90429A125 4-48 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.
• Superior thread precision with Class 3A fit provides tighter tolerances and improved vibration resistance, enhancing assembly integrity and longevity.
• Durable black-oxide finish on alloy steel offers enhanced corrosion resistance, extending service life in various industrial environments.
• Fine UNF thread spacing allows for finer adjustments and a more secure hold in materials, minimizing the chance of loosening over time.
• Fully threaded design maximizes grip along the entire length, providing uniform clamping force and versatility in different material thicknesses.
• 82° countersink angle and flat head enable a flush fit in pre-drilled holes, reducing protrusion and improving safety and aesthetics in assembled products.
• Hex drive compatibility with a 1/16" drive size facilitates easy installation and removal using standard tools, speeding up maintenance and assembly processes.

Professional Applications & Engineering Value

This 4-48 UNF flat head socket cap screw is engineered to address critical challenges in precision assembly and heavy-duty applications. Made from black-oxide alloy steel, it combines high Rockwell C39 hardness with excellent fatigue resistance, making it ideal for machinery, automotive, and aerospace components where vibration and load stresses are common. The fine thread spacing and Class 3A thread fit ensure minimal backlash and secure fastening in thin or brittle materials, while the fully threaded design distributes stress evenly to prevent joint failure. Its 82° countersink angle allows for seamless integration into countersunk holes, reducing aerodynamic drag or snag risks in enclosed systems. By meeting rigorous standards like ASME B18.3, this screw delivers consistent performance in industrial fastening solutions, enhancing reliability and reducing downtime in high-stakes environments.

Specification Summary & Compliance

This product adheres to precise dimensional tolerances, including Class 3A thread fit for superior accuracy and UNF fine thread type with right-hand direction. It complies with ASME B18.3 and ASTM F835 specifications for mechanical and material properties, ensuring consistent quality. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, supporting environmental and safety regulations in global supply chains.