S-91274A488 1/2"-13 x 3 3/4" 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 industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the zinc-flake coating extends service life in harsh environments, minimizing maintenance and replacement costs.
• Precise Class 3A thread fit guarantees secure, vibration-resistant connections, enhancing assembly integrity and safety.
• Partially threaded design allows for controlled clamping force and easier alignment in precision machinery and equipment.
• High hardness (Rockwell C37) provides excellent wear resistance, maintaining thread integrity through repeated use and disassembly.
• 3/8" hex drive compatibility offers efficient installation with standard tools, speeding up assembly processes in manufacturing and maintenance.
• Compliance with ASME B18.3 and ASTM standards ensures consistent quality and interoperability in regulated industrial settings.

Professional Applications & Engineering Value

This 1/2"-13 UNC Socket Head Cap Screw is engineered for demanding applications where reliability and durability are critical. The zinc-flake-coated alloy steel construction provides robust protection against corrosion, making it ideal for outdoor equipment, automotive assemblies, and heavy machinery exposed to moisture and chemicals. The coarse thread spacing and Class 3A thread fit deliver superior grip and vibration resistance, preventing loosening in dynamic environments. With a partially threaded rod, it offers precise clamping in jigs, fixtures, and structural frames, reducing stress concentration. Its high tensile strength and Rockwell C37 hardness ensure long-term performance in construction, aerospace, and industrial automation, meeting rigorous engineering standards for safety and efficiency.

Specification Summary & Compliance

This socket head cap screw features a 1/2"-13 UNC thread with Class 3A fit for precise tolerance, ensuring consistent thread engagement. It adheres to ASME B18.3 for dimensional accuracy and is manufactured per ASTM A574 (alloy steel) and ASTM B117 (corrosion testing). The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), supporting environmentally responsible and safe industrial use.