S-97832A140 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 environments and extended service life.
• Exceptional mechanical strength offering 70,000 psi tensile strength and 35,000 psi minimum shear strength for reliable performance under high-stress conditions.
• Precision alignment and smooth rotation enabled by the 2-1/2" shoulder with controlled diameter tolerance, reducing wear on mating parts.
• Secure and efficient installation with a 1/4" hex drive and knurled head for superior grip and torque application without slippage.
• Consistent and reliable thread engagement due to the Class 3A thread fit and coarse 5/16"-18 UNC thread, ensuring vibration resistance and easy assembly.
• Compliance with stringent industry standards including ASME B18.3, RoHS 3, and REACH, guaranteeing quality and environmental safety for global applications.
• Optimized for durability with a Rockwell B55 hardness, providing excellent wear resistance and long-term operational integrity.

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical alignment and load-bearing challenges in precision assemblies. The 18-8 stainless steel material offers inherent corrosion resistance, making it suitable for applications in machinery, automotive, and electronics where exposure to moisture or chemicals is a concern. The 2-1/2" shoulder length and precise shoulder diameter provide a stable pivot or spacer, minimizing misalignment and reducing wear on components like bearings and gears. With a coarse UNC thread and Class 3A fit, it ensures quick, secure fastening in high-vibration environments, while the hex drive and knurled head enhance installation efficiency. Ideal for use in jigs, fixtures, and rotating assemblies, this screw delivers reliable performance, reducing maintenance needs and downtime in industrial settings.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, ensuring dimensional accuracy and interchangeability. Key tolerances include a shoulder diameter of 1/2" with a tolerance of -0.004" to -0.002" and a shoulder length of 2-1/2" with a tolerance of -0.005" to 0.005". The threads are 5/16"-18 UNC with a Class 3A fit for precise engagement. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in various industrial applications without hazardous substances.