S-90311A114 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel construction, ideal for harsh environments and extended service life.
• Vibration-resistant locking provided by the integral nylon patch, preventing loosening in dynamic applications from -50° to 250°F.
• High-strength performance with 70,000 psi tensile strength and 35,000 psi minimum shear strength for demanding mechanical assemblies.
• Precise and reliable fit ensured by the Class 3A thread fit, reducing the risk of cross-threading and ensuring consistent clamping force.
• Easy installation and removal with a 5/64" hex socket drive and knurled head for improved grip and torque application.
• Durable and hard-wearing material with a Rockwell B79 hardness, resisting wear and deformation under load.
• Broad industrial compliance meeting RoHS 3 and REACH regulations, ensuring safety and environmental standards are met.

Professional Applications & Engineering Value

This 4-40 UNC shoulder screw is engineered to address critical challenges in precision assemblies, such as in electronics, aerospace, and automated machinery. The 316 Stainless Steel offers exceptional resistance to chemicals and moisture, preventing failure in corrosive settings. The nylon patch thread locker secures the right-hand coarse thread against vibrations, a common cause of joint failure in moving parts. With its Class 3A thread fit and knurled socket head, it ensures accurate alignment and easy servicing, reducing downtime. This combination of high tensile strength and locking feature makes it a reliable choice for applications requiring both structural integrity and secure fastening under thermal cycling and dynamic loads.

Specification Summary & Compliance

This shoulder screw features a 4-40 UNC coarse thread with a precision Class 3A thread fit and a thread length of 5/32". The shoulder diameter is 1/8" with a tolerance of -0.004" to -0.002", and the shoulder length is 5/16" with a tolerance of -0.005" to 0.005". It is manufactured to high standards, ensuring dimensional accuracy and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in regulated industrial and commercial applications without hazardous substances.