S-90298A624 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh environments and extended service life.
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance under high-stress conditions.
• Precise component alignment enabled by the shoulder with a tight diameter tolerance of ±0.001" and length tolerance of ±0.005", ensuring accurate assembly.
• Secure and efficient installation with a standard hex socket drive and knurled head, providing excellent grip and reducing the risk of tool slippage.
• High-reliability threaded connection due to the Class 3A thread fit and coarse UNC thread, facilitating quick assembly and strong holding power.
• Broad industry compliance meeting ASME B18.3 specifications and being RoHS 3 and REACH compliant for safe, regulated use in various sectors.
• Versatile design combining a 1/2" thread length and 1" shoulder length to accommodate diverse spacing and pivoting needs in assemblies.

Professional Applications & Engineering Value

This 18-8 stainless steel shoulder screw is engineered to address critical challenges in precision machinery, automation systems, and heavy-duty industrial equipment. The passivated finish enhances corrosion resistance, making it suitable for environments exposed to moisture or chemicals, while the high tensile strength of 70,000 psi ensures durability under dynamic loads. The precision shoulder with minimal tolerances allows for exact alignment of components such as gears, bearings, and linkages, reducing wear and preventing misalignment failures. Its coarse UNC thread and Class 3A fit provide a secure, vibration-resistant connection, ideal for applications in robotics, automotive assemblies, and conveyor systems where reliability is paramount. By integrating a knurled head and hex socket drive, it supports quick, tool-friendly installation, streamlining maintenance and reducing downtime in production lines.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 standards, ensuring dimensional accuracy and interoperability. The thread fit is Class 3A, providing a high degree of precision for secure fastening. Key dimensions include a shoulder diameter of 3/8" with a tolerance of -0.001" to 0.001" and a shoulder length of 1" with a tolerance of -0.005" to 0.005". It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of hazardous substances and supporting environmentally responsible manufacturing practices.