S-91327A291 6-32 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with nylon patch ensures secure fastening in dynamic applications, maintaining integrity from -50° to 250° F
• Superior corrosion resistance from 18-8 stainless steel and passivated finish extends service life in harsh industrial environments
• High tensile strength of 70,000 psi and Rockwell B55 hardness provide reliable load-bearing capacity for demanding assemblies
• Precision Class 3A thread fit guarantees consistent engagement and reduces the risk of cross-threading during installation
• Standard UNC coarse threads enable quick assembly and disassembly, saving time in maintenance and production cycles
• Hex socket drive design allows for easy access in confined spaces with standard tools, improving installation efficiency
• Compliance with ASME B18.3, RoHS 3, and REACH ensures adherence to industry standards and environmental safety regulations

Professional Applications & Engineering Value

This 6-32 UNC shoulder screw is engineered to address common challenges in precision machinery, such as component misalignment and vibration-induced loosening. The 18-8 stainless steel construction, combined with a passivated finish, offers excellent resistance to corrosion and wear, making it ideal for applications in automotive, aerospace, and electronic enclosures where exposure to moisture and chemicals is a concern. The integrated nylon patch thread locker provides reliable locking without the need for additional adhesives, ensuring stable performance in temperature-varying environments from -50° to 250° F. Its coarse thread design and Class 3A fit facilitate smooth assembly in high-volume production, reducing downtime and enhancing operational reliability. This screw is particularly valuable in pivot points, rotating assemblies, and precision guides, where the shoulder acts as a precise spacer or bearing surface.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit with UNC coarse threads, ensuring tight tolerances for reliable fastening. It adheres to ASME B18.3 manufacturing specifications, with a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005" for consistent performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in various industrial and consumer applications without hazardous substances.