S-91205A625 3/8"-16 x 1 1/8" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Superior vibration resistance with integrated Nylon Patch thread locker, preventing loosening in dynamic applications from -70° to 250°F.
• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress industrial conditions.
• Enhanced durability and corrosion resistance from Black-Oxide Alloy Steel with Rockwell C37 hardness for long service life.
• Precise Class 3A thread fit guarantees secure, accurate mating with coarse UNC threads for easy assembly and reduced cross-threading risk.
• Optimized hex drive design with 5/16" drive size and standard socket head profile for efficient torque application and access in confined spaces.
• Full thread coverage along the 1 1/8" length provides consistent clamping force and flexibility in various material thicknesses.
• Compliance with major industrial standards including ASME B18.3 and ASTM A574, ensuring quality and reliability for critical applications.

Professional Applications & Engineering Value

This 3/8"-16 UNC Socket Head Cap Screw is engineered to address common industrial challenges such as vibration-induced loosening and high-load demands. The Black-Oxide Alloy Steel construction offers excellent wear resistance and protection against environmental factors, while the Nylon Patch thread locker embedded in the threads provides reliable locking without requiring additional adhesives. Ideal for machinery, automotive, and aerospace assemblies, the coarse thread spacing and Class 3A thread fit ensure quick installation and secure fastening in metals and composites. Its fully threaded design and hex drive facilitate uniform stress distribution and easy maintenance, reducing downtime in production lines and enhancing operational efficiency.

Specification Summary & Compliance

This screw features a 3/8"-16 UNC thread with Class 3A precision fit and coarse thread spacing, ensuring dimensional accuracy per ASME B18.3. It is manufactured from Alloy Steel under ASTM A574 specifications, with a tensile strength of 170,000 psi and hardness of Rockwell C37. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious and safe industrial use.