S-91264A595 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 140,000 psi tensile strength and 84,000 psi shear strength for reliable performance in demanding applications.
• Secure vibration-resistant locking provided by the integrated nylon pellet, maintaining fastener integrity from -50° to 250° F without loosening.
• Precise alignment and smooth rotation due to the knurled head and standard shoulder fit, reducing wear in machinery assemblies.
• High corrosion resistance from the black oxide finish, extending service life in harsh industrial environments.
• Superior thread accuracy with Class 3A UNC coarse threads ensuring easy installation and consistent clamping force.
• Robust material construction using alloy steel with Rockwell C32 hardness for durability and repeated use without deformation.
• Wide regulatory compliance including ASME B18.3, RoHS, and REACH, ensuring safety and environmental standards are met.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in industrial applications where precision and reliability are paramount. The 3" shoulder length provides a stable bearing surface for rotating components like gears and pulleys, minimizing misalignment and reducing friction. The black oxide finish offers enhanced corrosion resistance, ideal for environments exposed to moisture or chemicals. With a coarse UNC thread and Class 3A fit, it ensures quick assembly and high clamping force, while the nylon pellet thread locker prevents loosening under vibration, common in automotive and machinery systems. This combination of high tensile strength and secure locking makes it a top choice for heavy-duty fastening in manufacturing and equipment maintenance.

Specification Summary & Compliance

This shoulder screw features precise dimensions including a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005" for accurate fits. It adheres to ASME B18.3 standards with Class 3A thread fit and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and quality in production.