S-91259A499 8-32 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 140,000 psi tensile strength and 84,000 psi shear strength for reliable performance in high-stress applications.
• Precision alignment and secure positioning thanks to the 3/4" ground shoulder with tight diameter and length tolerances for consistent fit.
• Superior corrosion resistance and reduced galling from the black oxide finish, extending service life in demanding environments.
• High-strength durability provided by alloy steel construction and Rockwell C32 hardness, resisting wear and deformation.
• Easy installation and removal with the hex socket drive and 3/32" drive size, allowing efficient assembly with standard tools.
• Secure thread engagement ensured by Class 3A thread fit and 8-32 UNC coarse threads for quick, reliable fastening.
• Full regulatory compliance with ASME B18.3, ASTM A574, RoHS 3, and REACH, ensuring safety and environmental standards are met.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical alignment and rotational stability challenges in industrial machinery. The precision-ground shoulder provides a consistent bearing surface for components like gears, pulleys, and linkages, minimizing misalignment and reducing wear. Its high tensile strength and black oxide finish make it ideal for applications in automotive assemblies, robotics, and precision equipment, where resistance to vibration and corrosion is essential. The socket head design with hex drive allows for compact installation in confined spaces, while the 8-32 UNC coarse threads facilitate quick assembly without compromising holding power. By integrating robust materials and exacting tolerances, this screw enhances operational reliability and reduces maintenance needs in B2B industrial settings.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit for precise engagement and features a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005" for accurate alignment. It conforms to ASME B18.3 and ASTM A574 specifications, ensuring consistent manufacturing quality. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmental and safety standards in global supply chains.