S-91264A594 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Permanent vibration resistance with nylon pellet thread locking, maintaining secure fastening from -50° to 250° F in demanding environments.
• Exceptional load-bearing capacity due to 140,000 psi tensile strength and 84,000 psi minimum shear strength, ideal for high-stress applications.
• Precise alignment and smooth rotation enabled by the 2 3/4" shoulder with standard fit and tight diameter tolerance for reliable assembly.
• Superior durability and corrosion resistance from the alloy steel construction with black oxide finish, extending service life.
• Easy installation and removal with the hex socket drive and knurled head, providing a secure grip and reducing tool slippage.
• Reliable thread engagement thanks to Class 3A thread fit and 5/16"-18 UNC coarse threads, ensuring consistent performance.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, guaranteeing quality and environmental safety.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in industrial machinery, automation, and precision equipment where alignment, vibration, and high loads are concerns. The 2 3/4" shoulder length provides a stable bearing surface for rotating parts like gears and pulleys, minimizing wear and ensuring accurate positioning. With a black oxide finish, it offers enhanced corrosion resistance in harsh conditions, while the nylon pellet locking feature prevents loosening under continuous vibration, reducing maintenance needs. The UNC coarse threads and Class 3A fit deliver reliable fastening in assemblies requiring repeated adjustments, making it a trusted choice for robotics, automotive, and heavy-duty applications that demand long-term reliability and ease of use.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit and UNC thread standards for precise dimensional accuracy, with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005". It meets ASME B18.3 specifications and is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safety and sustainability in industrial use.