S-90298A707 3/8"-16 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel construction and passivated finish, ensuring long-term reliability in harsh environments.
• High-strength performance offering 70,000 psi tensile strength and Rockwell B55 hardness for demanding industrial applications.
• Precise shoulder alignment with a 1/2" diameter held to ±0.001" tolerance, enabling accurate component positioning and reduced assembly time.
• Secure hex drive engagement via a 1/4" hex socket and knurled head, providing non-slip torque application and easy installation.
• Reliable thread integrity with Class 3A UNC coarse threads, ensuring consistent fastening and vibration resistance in right-hand threaded assemblies.
• Broad compliance with ASME B18.3 specifications, RoHS 3, and REACH, meeting strict industry and environmental standards.
• Durable surface protection from the passivated finish, enhancing wear resistance and extending service life in mechanical systems.

Professional Applications & Engineering Value

This 3/8"-16 UNC shoulder screw is engineered to address critical alignment and durability challenges in precision machinery. The 18-8 Stainless Steel material, combined with a passivated finish, provides excellent resistance to corrosion and oxidation, making it ideal for applications in automotive, aerospace, and manufacturing equipment where exposure to moisture or chemicals is common. The 1/2" shoulder diameter with tight tolerances ensures exact positioning of rotating parts like gears and pulleys, reducing wear and minimizing maintenance downtime. Its Class 3A thread fit and coarse UNC threads offer robust fastening in high-vibration environments, while the socket head with hex drive allows for efficient installation in confined spaces. By integrating these features, this shoulder screw enhances assembly accuracy, load distribution, and overall system longevity in industrial applications.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 standards, with a Class 3A thread fit for precise UNC threading. Key dimensional tolerances include a shoulder diameter of 1/2" (±0.001") and shoulder length of 1/2" (±0.005"), ensuring high accuracy. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible manufacturing and use.