S-91205A069 2-56 x 3/4" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with integrated Nylon Patch thread locker prevents loosening in high-stress applications, ensuring long-term joint integrity.
• Exceptional tensile strength of 170,000 psi provides reliable performance under heavy loads, reducing the risk of fastener failure.
• Wide temperature tolerance from -70°F to 250°F maintains mechanical properties and locking effectiveness in diverse operating environments.
• Superior thread precision with Class 3A fit ensures consistent engagement and reliable clamping force for critical assemblies.
• Enhanced corrosion resistance from the Black-Oxide finish on Alloy Steel extends service life in demanding industrial conditions.
• Optimized drive engagement with the 5/64" hex socket allows for high torque application and reduces the risk of tool slippage.
• Full thread coverage along the 3/4" length provides maximum adjustment flexibility and uniform stress distribution.

Professional Applications & Engineering Value

This Socket Head Cap Screw is engineered to address critical challenges in precision assembly and machinery. The Black-Oxide Alloy Steel construction, combined with a Rockwell C37 hardness, offers an optimal balance between strength and ductility, resisting shear and tensile failures in high-vibration environments like automotive subsystems, robotics, and aerospace components. The integrated Nylon Patch thread locker actively counters vibrational loosening, eliminating the need for separate locking washers or adhesives, which streamlines inventory and assembly processes. Its 2-56 UNC coarse thread and Class 3A fit ensure rapid installation and reliable engagement in metals and engineered plastics, making it a preferred choice for OEMs and maintenance teams requiring durable, temperature-stable fasteners from -70° to 250° F.

Specification Summary & Compliance

This screw adheres to ASME B18.3 dimensional standards and is manufactured from Alloy Steel per ASTM A574. Thread specifications include a 2-56 UNC coarse thread with a precision Class 3A thread fit and right-hand direction. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it meets global environmental and safety standards for industrial use.