S-91205A726 1/2"-13 x 4" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, minimizing failure risks in demanding applications.
• Secure vibration resistance with a nylon patch thread locker that maintains locking integrity across a wide temperature range from -70° to 250°F.
• Precise Class 3A thread fit provides superior engagement and reduces the likelihood of cross-threading, enhancing assembly efficiency.
• Durable black-oxide coating on alloy steel offers corrosion resistance and a professional finish, extending service life in harsh environments.
• Hex socket drive design allows for high-torque installation with standard 3/8" tools, facilitating easy access in confined spaces.
• Partially threaded shank enables optimal clamping force distribution, ideal for applications requiring precise joint stability.
• Compliance with ASME B18.3 and material standards ensures consistent quality and interoperability in industrial assemblies.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in heavy-duty machinery, automotive, and aerospace sectors where vibration loosening and high tensile loads are common. The UNC coarse thread design facilitates quick assembly and disassembly, while the nylon patch thread locker effectively counters dynamic stresses without requiring additional adhesives. With a Rockwell C37 hardness and robust alloy steel construction, it withstands repetitive loading and extreme temperatures, making it suitable for engine components, structural frames, and precision equipment. The hex drive and standardized dimensions ensure compatibility with common tools, streamlining maintenance and reducing downtime in industrial operations.

Specification Summary & Compliance

This screw features a 1/2"-13 UNC coarse thread with Class 3A tolerance for precise fit, a partially threaded rod, and a minimum thread length of 1-1/2". It conforms to ASME B18.3 specifications and is manufactured from ASTM A574 material. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and regulatory adherence for global supply chains.