S-97832A271 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel construction, ideal for harsh industrial environments and reducing replacement frequency
• High-torque installation capability thanks to the hex drive and knurled socket head, preventing tool slippage and ensuring secure fastening
• Exceptional load-bearing strength with 70,000 psi tensile and 35,000 psi shear strength, providing reliable performance under high stress
• Precise component alignment enabled by the 3/8" shoulder diameter with tight tolerance, minimizing assembly play and vibration
• Durable thread engagement from Class 3A UNC coarse threads, offering faster assembly and resistance to loosening in dynamic applications
• Broad regulatory compliance including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental standards for global supply chains
• Optimized for repetitive use with Rockwell B55 hardness, maintaining structural integrity and thread form over multiple installations

Professional Applications & Engineering Value

This 5/16"-18 UNC shoulder screw is engineered to address critical alignment and durability challenges in industrial applications such as machinery assemblies, pivoting mechanisms, and precision fixtures. The 18-8 Stainless Steel material provides excellent resistance to rust and chemical exposure, extending service life in demanding conditions. The 3/8" shoulder diameter with controlled tolerance acts as a precise locating dowel, eliminating misalignment and reducing wear on mated parts. Combined with the knurled socket head and hex drive, it ensures secure, high-torque installation without cam-out, making it ideal for maintenance-heavy environments. The coarse UNC thread and Class 3A fit facilitate quick assembly while maintaining strong clamping force, solving common issues of vibration-induced loosening in moving equipment.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with precise dimensional controls including a shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005". The UNC thread is manufactured to Class 3A fit standards, ensuring consistent engagement and strength. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in regulated industries and environmentally conscious supply chains.