S-91274A476 1/2"-13 x 3" ASME B18.3, ASTM A574, ASTM B117 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the zinc-flake coating extends service life in harsh industrial environments, minimizing maintenance and replacement costs.
• Precision Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, enhancing joint integrity.
• High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread and drive integrity through repeated use.
• 3/8" hex drive design allows for easy installation and high torque application with standard tools, improving assembly efficiency.
• Partially threaded shank enables precise clamping force distribution, ideal for applications requiring controlled grip length.
• Compliance with ASME B18.3 and ASTM A574 guarantees consistent quality and interchangeability, ensuring compatibility with industry standards.

Professional Applications & Engineering Value

This zinc-flake-coated alloy steel socket head cap screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, automotive systems, and structural frameworks. The 1/2"-13 UNC coarse thread design ensures rapid installation and robust holding power, while the Class 3A thread fit minimizes backlash in high-vibration environments. The zinc-flake coating provides a durable barrier against moisture, chemicals, and UV exposure, significantly reducing corrosion-related failures. With a 3-inch length and partially threaded configuration, it offers versatility for applications requiring precise unthreaded shank sections, such as aligning components or distributing clamp load effectively. Ideal for OEMs and maintenance teams, this fastener delivers long-term reliability in demanding conditions, from manufacturing plants to outdoor equipment.

Specification Summary & Compliance

This socket head cap screw adheres to Class 3A thread tolerances for inch-system applications, ensuring precise fit and performance. It conforms to ASME B18.3 and ASTM A574 specifications for dimensional accuracy and material integrity. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible sourcing and use in global markets.