S-91327A150 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with integrated nylon patch that maintains secure fastening in temperatures from -50° to 250°F, preventing loosening in dynamic applications.
• Superior corrosion resistance thanks to 18-8 Stainless Steel construction and passivated finish, ensuring long-term durability in harsh industrial environments.
• High tensile strength of 70,000 psi and Rockwell B55 hardness for reliable performance under heavy loads and repeated use.
• Precise Class 3A thread fit and UNC coarse threading for easy assembly, reduced cross-threading risk, and consistent engagement.
• Knurled head and 3/16" hex drive design for improved grip and torque application, facilitating quick installation and removal with standard tools.
• Accurate shoulder dimensions with tight tolerances (e.g., shoulder diameter tolerance of -0.004" to -0.002") for precise alignment in machinery and assemblies.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety, quality, and environmental responsibility.

Professional Applications & Engineering Value

This 5/16"-18 UNC shoulder screw is engineered to address common industrial challenges such as component misalignment, vibration-induced failures, and corrosion in demanding settings. Machined from 18-8 Stainless Steel with a passivated finish, it resists rust and wear in applications like automated machinery, conveyor systems, and precision instruments. The nylon patch thread locker secures fasteners against loosening from shocks or temperature fluctuations (-50° to 250°F), while the Class 3A thread fit and coarse UNC threads enable quick, reliable assembly. Ideal for industrial fastening in robotics, automotive, and aerospace, it ensures dimensional stability with its accurately machined shoulder, reducing downtime and maintenance costs.

Specification Summary & Compliance

This shoulder screw features a 5/16"-18 UNC thread with Class 3A fit for high precision, a shoulder diameter of 3/8" (tolerance: -0.004" to -0.002"), and a shoulder length of 1/4" (tolerance: -0.005" to 0.005"). It meets ASME B18.3 specifications for dimensional consistency and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and suitable for global industrial use.