S-91205A595 5/16"-18 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 in high-stress industrial applications
• Nylon patch thread locker maintains secure fastening across a wide temperature range from -70° to 250°F
• Black-oxide coating on alloy steel provides corrosion resistance and enhanced durability in demanding environments
• Class 3A thread fit delivers superior precision and consistent engagement for vibration-resistant assemblies
• Partially threaded design allows for optimal clamping force distribution and simplified installation
• 1/4" hex drive socket head enables high-torque application with standard tools while minimizing strip-out risk
• Coarse UNC thread pattern ensures quick assembly and disassembly in industrial maintenance scenarios

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw addresses critical engineering challenges in industrial machinery, automotive assemblies, and heavy equipment applications. The combination of 170,000 psi tensile strength and Rockwell C37 hardness provides exceptional resistance to shear forces and fatigue, while the nylon patch thread locking feature prevents loosening under vibration - a common failure point in dynamic systems. The 5/16"-18 UNC coarse thread configuration ensures rapid installation in time-sensitive maintenance operations, and the partially threaded design concentrates clamping force precisely where needed. These socket head cap screws are engineered to maintain integrity in high-vibration environments where fastener failure could lead to costly downtime or safety concerns.

Specification Summary & Compliance

This fastener features Class 3A thread fit precision with 5/16"-18 UNC coarse threads and partial threading configuration. Manufactured to ASME B18.3 specifications using ASTM A574 alloy steel material. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for global industrial applications with strict chemical substance restrictions.