S-97768A409 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and black oxide finish for extended service life in harsh environments
• Precise component alignment through Class 3A thread fit and controlled shoulder diameter tolerances for reliable assembly
• High mechanical strength delivering 70,000 psi tensile strength and 35,000 psi shear strength for demanding applications
• Secure installation and removal with hex socket drive and knurled head design preventing tool slippage
• Industry-standard compatibility meeting ASME B18.3 specifications for consistent performance across equipment
• Environmental compliance with RoHS 3 and REACH regulations for safe use in regulated industries
• Optimized for high-vibration applications through coarse UNC threading and right-hand thread direction

Professional Applications & Engineering Value

This 5/16"-18 UNC shoulder screw delivers exceptional engineering value in precision assembly applications where alignment accuracy and durability are critical. The 18-8 stainless steel core provides excellent mechanical properties while the black oxide finish enhances corrosion resistance in industrial environments. The precisely machined 1/2" shoulder diameter with tight tolerances ensures proper component spacing and rotational stability in machinery, automation systems, and precision instruments. The Class 3A thread fit and coarse UNC threading maintain secure fastening under vibration and dynamic loads, while the socket head with hex drive facilitates installation in confined spaces. These features make it ideal for pivot points, rotating assemblies, and precision guiding mechanisms across manufacturing, automotive, and industrial equipment sectors.

Specification Summary & Compliance

This shoulder screw features Class 3A thread fit with UNC coarse threading (5/16"-18) and maintains precise dimensional control with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005". Manufactured to ASME B18.3 specifications, the component demonstrates Rockwell B55 hardness and meets comprehensive compliance standards including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations for environmental safety and restricted substance control.