S-91205A066 2-56 x 1/2" 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, reducing the risk of fastener failure in demanding applications.
• Integrated nylon patch thread locker provides vibration-resistant locking from -70° to 250°F, maintaining joint integrity without requiring separate adhesives.
• Class 3A precision thread fit offers superior engagement and consistent clamping force, minimizing loosening in critical assemblies.
• Black-oxide coating on alloy steel enhances corrosion resistance and provides a durable, non-galling surface for extended service life.
• Hex socket drive design allows for high-torque installation in confined spaces, improving assembly efficiency and reducing tool slip.
• Compliance with ASME B18.3 and ASTM A574 guarantees dimensional accuracy and material consistency, ensuring interchangeability and reliability.
• RoHS 3 and REACH compliance meets international environmental standards, making these screws suitable for global supply chains and regulated industries.

Professional Applications & Engineering Value

Engineered for precision industrial fastening, these socket head cap screws with 2-56 UNC coarse threads and Class 3A fit address common challenges like vibration-induced loosening and space constraints. The black-oxide alloy steel construction provides excellent strength-to-weight ratio, ideal for machinery, automotive, and electronics where high tensile strength and corrosion resistance are critical. The integrated nylon patch thread locker eliminates the need for additional locking mechanisms, streamlining assembly while ensuring secure joints from -70° to 250°F. This combination of material durability and thread precision reduces maintenance cycles and enhances operational reliability in dynamic environments.

Specification Summary & Compliance

This screw features a 2-56 UNC coarse thread with Class 3A fit for precise engagement, manufactured to ASME B18.3 and ASTM A574 specifications. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, ensuring environmental safety and material quality for industrial use.