S-91264A583 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with nylon pellet thread locker maintains secure fastening in temperatures from -50° to 250°F, reducing maintenance needs in dynamic environments.
• Exceptional strength and durability from alloy steel construction, offering 140,000 psi tensile strength and 84,000 psi shear strength for heavy-duty industrial applications.
• Precise Class 3A thread fit ensures reliable engagement and reduces the risk of cross-threading during assembly, improving installation efficiency.
• Corrosion-resistant black oxide finish enhances longevity by protecting against rust and wear in harsh operating conditions.
• Easy installation and removal with a standard hex drive socket head and knurled texture for better grip, minimizing tool slippage.
• Accurate shoulder dimensions with tight tolerances (e.g., shoulder diameter tolerance of -0.004" to -0.002") provide consistent alignment in machinery and pivoting mechanisms.
• Compliance with industry standards including ASME B18.3 and RoHS 3/REACH, ensuring safety and environmental responsibility in global supply chains.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address common industrial challenges such as component misalignment and vibration-induced loosening. The 5/16"-18 UNC coarse threads with a nylon pellet thread locker deliver reliable performance in assemblies subject to thermal cycling and dynamic loads, from -50° to 250°F. The black oxide finish not only resists corrosion but also reduces friction during installation. Ideal for precision machinery, automotive systems, and pivoting joints, the socket head design with hex drive allows for tight spaces and high-torque applications. Its knurled head enhances grip, while the 1" shoulder length and 3/8" shoulder diameter ensure exact positioning, minimizing wear and extending service life in demanding environments.

Specification Summary & Compliance

This shoulder screw features Class 3A thread fit for high precision and adheres to ASME B18.3 specifications under ASTM A574. Key dimensions include a thread size of 5/16"-18 UNC, shoulder diameter of 3/8" with a tolerance of -0.004" to -0.002", and shoulder length of 1" with a tolerance of -0.005" to 0.005". It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it meets environmental and safety standards for industrial use.