S-91264A576 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Secure vibration-resistant locking with nylon pellet thread locker, maintaining integrity across a wide temperature range from -50° to 250° F
• Exceptional load-bearing capacity with 140,000 psi tensile strength and 84,000 psi minimum shear strength for demanding industrial applications
• Precision alignment and smooth rotation thanks to the 3/8" shoulder diameter with tight tolerances (-0.004" to -0.002") for consistent component positioning
• Enhanced durability and corrosion resistance from the alloy steel construction with black oxide finish and Rockwell C32 hardness
• Reliable coarse thread engagement with 5/16"-18 UNC Class 3A threads ensuring quick assembly and high resistance to loosening
• Easy installation in confined spaces using the standard socket head with 3/16" hex drive and knurled head texture for improved grip
• Full regulatory compliance meeting ASME B18.3 specifications, RoHS 3, and REACH for global industrial use

Professional Applications & Engineering Value

This alloy steel shoulder screw delivers critical performance in precision machinery, automation systems, and heavy-duty equipment where alignment and vibration resistance are paramount. The black oxide finish provides superior corrosion protection in harsh environments, while the nylon pellet thread locker eliminates the need for additional locking hardware, reducing assembly time and preventing costly downtime from loosening. Engineered with Class 3A UNC coarse threads and a precisely machined shoulder, it ensures accurate component spacing and smooth pivoting in linkages, bearings, and rotating assemblies. The socket head design with hex drive allows for high-torque installation in tight spaces, making it ideal for industrial applications requiring reliable, high-strength fastening solutions.

Specification Summary & Compliance

This shoulder screw features precision 5/16"-18 UNC Class 3A threads with 1/2" thread length and a 3/8" shoulder diameter (tolerance: -0.004" to -0.002") and length (tolerance: -0.005" to 0.005"). Manufactured to ASME B18.3 specifications using ASTM A574 alloy steel, it complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe and sustainable use across global industrial markets.