S-90311A112 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-proof locking with permanent nylon patch thread locker that maintains secure fastening from -50° to 250°F, reducing maintenance needs in dynamic environments.
• Superior corrosion resistance thanks to 316 stainless steel construction, ideal for harsh or chemical-exposed industrial settings.
• High-strength performance with 70,000 psi tensile strength and 35,000 psi shear strength, ensuring reliable load-bearing in precision assemblies.
• Precise thread engagement via Class 3A thread fit and UNC coarse threading, providing consistent installation and reduced risk of cross-threading.
• Easy installation and removal with 5/64" hex socket drive and knurled head texture, offering improved grip and torque application.
• Durable shoulder design featuring a standardized shoulder fit and tight diameter tolerance, enabling accurate alignment in machinery components.
• Regulatory compliance with RoHS 3 and REACH standards, ensuring safe use in global markets and eco-sensitive applications.

Professional Applications & Engineering Value

This 4-40 UNC shoulder screw in 316 stainless steel is engineered to address critical challenges in industrial and precision assemblies, such as vibration-induced loosening and corrosion. The nylon patch thread locker provides a permanent locking mechanism that withstands temperature fluctuations from -50° to 250°F, making it suitable for automotive, aerospace, and electronic enclosures where reliability is paramount. Its coarse UNC threads and Class 3A fit ensure quick, secure fastening with high repeatability, while the knurled socket head allows for efficient torque transfer in confined spaces. By combining robust tensile and shear strength with excellent chemical resistance, this fastener minimizes downtime and enhances the longevity of equipment in demanding environments.

Specification Summary & Compliance

This shoulder screw adheres to UNC thread standards with a Class 3A thread fit for precise engagement, and features a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005" to ensure consistent performance. Manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it meets international environmental and safety requirements for industrial use.