S-90128A255 1/4"-20 x 2 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi provides reliable performance in high-stress applications, reducing the risk of fastener failure.
• Zinc-plated alloy steel construction offers superior corrosion resistance, extending the screw's service life in demanding industrial environments.
• Class 3A thread fit ensures precise, secure mating with nuts and tapped holes, minimizing backlash and improving assembly reliability.
• Hex socket drive allows for high torque application and easy installation in confined spaces, enhancing assembly efficiency.
• Partially threaded design provides an unthreaded shoulder for accurate component positioning and increased shear strength.
• Compliance with ASTM A574 guarantees consistent quality and mechanical properties, ensuring dependable performance in critical applications.
• RoHS 3 and REACH compliance makes this screw suitable for use in regulated industries and environmentally conscious projects.

Professional Applications & Engineering Value

This zinc-plated alloy steel socket head cap screw is engineered to solve common industrial fastening challenges, such as vibration loosening and corrosion-induced failure. The UNC coarse thread and Class 3A fit provide excellent engagement in a variety of materials, reducing the risk of cross-threading during assembly. Its high tensile strength and Rockwell C37 hardness make it ideal for heavy-duty machinery, automotive assemblies, and construction equipment where dynamic loads are present. The hex socket drive design is particularly valuable in applications with limited access, allowing mechanics to achieve proper clamp load without stripping the drive. This combination of material properties and precision manufacturing delivers reliable performance in industrial applications requiring durable, long-lasting fastening solutions.

Specification Summary & Compliance

This socket head cap screw features precision UNC threads with Class 3A fit for superior thread engagement and dimensional accuracy. The manufacturing process adheres to ASTM A574 specifications, ensuring consistent mechanical properties and quality control. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, making it suitable for use in environmentally sensitive applications and regulated industries.