S-94383A330 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional durability and corrosion resistance with a black oxide finish that protects against rust and wear in harsh industrial environments.
• Superior load-bearing capacity thanks to alloy steel construction, offering a tensile strength of 140,000 psi and shear strength of 84,000 psi for reliable performance under stress.
• Precise thread engagement and reduced risk of stripping with Class 3A thread fit and UNC coarse threads, ensuring secure fastening in high-vibration applications.
• Enhanced grip and easy installation from the knurled socket head and 3/16" hex drive, allowing for quick assembly without slippage.
• Accurate shoulder dimensions for consistent alignment with tight tolerances on shoulder diameter and length, minimizing play in precision machinery.
• Long-term reliability in demanding conditions supported by Rockwell C32 hardness, maintaining structural integrity over repeated use.
• Compliance with global standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental responsibility in B2B supply chains.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in industrial assemblies, such as misalignment and component wear. The black oxide finish provides a protective layer that reduces friction and resists corrosion, extending service life in environments like automotive or heavy machinery. With a 5/16"-18 UNC thread and coarse spacing, it ensures rapid installation and strong holding power in high-vibration settings, while the precise shoulder diameter and length tolerances enable exact positioning in rotating parts or linkages. Ideal for applications requiring socket head accessibility and knurled grip, it simplifies maintenance and reduces downtime, making it a cost-effective choice for OEMs and MRO operations focused on durability and efficiency.

Specification Summary & Compliance

The screw features a Class 3A thread fit for tight dimensional accuracy, with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005". It adheres to ASME B18.3 manufacturing standards and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it meets rigorous safety and environmental requirements for industrial use.