S-90128A856 1/2"-20 x 3" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in critical applications.
• Superior corrosion resistance from zinc-plated alloy steel construction extends service life and maintains integrity in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening over time.
• 3/8" hex drive design allows for high-torque installation with standard tools, speeding up assembly while preventing cam-out.
• Partially threaded shank offers optimal grip and clamping force distribution, ideal for materials requiring controlled tension.
• UNF fine thread configuration delivers enhanced holding power and finer adjustment capability compared to coarse threads.
• Compliance with ASTM A574, RoHS 3, and REACH ensures consistent quality and environmental safety for global industrial use.

Professional Applications & Engineering Value

This 1/2"-20 UNF Socket Head Cap Screw is engineered to address common challenges in heavy-duty machinery, automotive, and aerospace assemblies where vibration resistance and high clamp load are critical. The zinc-plated alloy steel material combats corrosion, while the Rockwell C37 hardness and 170,000 psi tensile strength prevent stripping and deformation under extreme loads. The fine UNF thread and Class 3A fit ensure precise engagement in tapped holes, reducing the risk of cross-threading and providing reliable performance in dynamic environments. Its partially threaded design concentrates clamping force where needed, making it ideal for securing components like engine blocks, hydraulic fittings, and structural frames without compromising joint integrity.

Specification Summary & Compliance

This socket head cap screw features a 1/2"-20 UNF fine thread with Class 3A thread fit for high precision, a minimum thread length of 1-1/2", and an overall length of 3". Manufactured to ASTM A574 specifications, it ensures consistent mechanical properties and dimensional accuracy. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing adherence to environmental and safety standards for industrial fastener applications.