S-91205A718 1/2"-13 x 1 3/4" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional holding power with 170,000 psi tensile strength for reliable performance in high-stress applications.
• Vibration-resistant locking provided by the Nylon Patch thread locker, maintaining secure fastening from -70° to 250°F.
• Superior wear resistance and durability thanks to Rockwell C37 hardness and Black-Oxide surface treatment on alloy steel.
• Precise, reliable threading with Class 3A fit and UNC coarse thread for easier alignment and stronger engagement.
• Easy installation in confined spaces using the standard socket head and 3/8" hex drive.
• Full thread coverage along the 1 3/4" length ensures consistent clamping force and versatile positioning.
• Compliance with major industrial standards including ASME B18.3 and ASTM A574 for guaranteed quality and interoperability.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to solve critical fastening challenges in demanding environments. The combination of high tensile strength (170,000 psi) and Rockwell C37 hardness ensures it withstands extreme mechanical loads without failing, making it ideal for heavy machinery, automotive assemblies, and construction equipment. The Nylon Patch thread locker effectively counters vibration-induced loosening, a common failure point in dynamic systems, maintaining clamp load integrity across a wide temperature range. Its UNC coarse thread and Class 3A fit provide superior resistance to stripping and cross-threading during installation, reducing assembly errors and maintenance downtime. The socket head design with a 3/8" hex drive allows for high-torque installation in tight spaces, enhancing efficiency in complex assemblies where wrench clearance is limited.

Specification Summary & Compliance

This screw features a 1/2"-13 UNC coarse thread with a precision Class 3A thread fit for accurate and secure engagement. It is manufactured in compliance with ASME B18.3 and ASTM A574 specifications, ensuring dimensional consistency and mechanical performance. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting stringent environmental and safety regulations for use in various global markets.