S-91205A636 3/8"-16 x 3" 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.
• Nylon patch thread locker provides vibration resistance and prevents loosening, maintaining clamp load integrity from -70° to 250°F without requiring separate locking components.
• Black-oxide coating on alloy steel offers corrosion resistance and a durable, non-galling surface that extends service life in harsh industrial environments.
• Class 3A thread fit delivers precise, tight-tolerance engagement for superior load distribution and reduced risk of cross-threading during assembly.
• 5/16" hex socket drive allows high-torque installation with standard tools, minimizing stripping and enabling efficient maintenance in confined spaces.
• Partially threaded shank design concentrates threads where needed, providing unthreaded bearing surfaces for improved shear strength and alignment.
• Compliance with ASME B18.3 and ASTM A574 guarantees consistent dimensional accuracy and material properties, ensuring interchangeability and reliability in OEM and MRO applications.

Professional Applications & Engineering Value

Engineered for high-stress assembly in machinery, automotive, and heavy equipment, this socket head cap screw solves critical fastening challenges. The black-oxide alloy steel construction resists corrosion while the coarse UNC threads enable rapid installation in tough materials. The integrated nylon patch thread locker eliminates the need for additional adhesives, providing secure retention in vibrating systems from -70° to 250°F. With 170,000 psi tensile strength and Rockwell C37 hardness, it withstands extreme loads without deformation, making it ideal for structural frames, engine components, and precision industrial equipment where failure is not an option.

Specification Summary & Compliance

This screw maintains Class 3A thread fit per UNC standards with 3/8"-16 coarse threading and 1½" minimum thread length. Manufacturing conforms to ASME B18.3 dimensional specifications and ASTM A574 material standards. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in global markets.