S-91259A452 5/8"-11 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 demanding applications.
• Superior corrosion resistance and reduced light reflection thanks to the black oxide finish, extending service life in harsh environments.
• Precise alignment and secure positioning enabled by the knurled head and standard shoulder fit, minimizing component slippage during assembly.
• High thread reliability and fatigue resistance from the Class 3A thread fit and coarse UNC thread, ensuring durable connections under vibration.
• Easy installation and high torque transmission with the 3/8" hex drive and socket head design, reducing assembly time and tool wear.
• Consistent mechanical properties due to Rockwell C32 hardness and alloy steel construction, providing dependable performance batch after batch.
• Compliance with major industry standards including ASME B18.3 and ASTM A574, guaranteeing interchangeability and quality assurance.

Professional Applications & Engineering Value

This 5/8"-11 UNC shoulder screw is engineered to address critical challenges in heavy-duty machinery, automation systems, and precision equipment. The alloy steel core, enhanced with a black oxide finish, combats wear and environmental degradation, making it ideal for applications exposed to moisture, chemicals, or constant operational stress. The knurled head provides superior grip during manual adjustments, while the standard shoulder ensures exact component spacing and rotational stability—key for aligning gears, pulleys, or bearings in industrial assemblies. With its coarse thread and Class 3A thread fit, it resists loosening under dynamic loads, reducing maintenance needs and downtime in sectors like automotive manufacturing, aerospace, and robotics.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit and UNC coarse thread standards for precise engagement. Manufacturing follows ASME B18.3 and material specifications meet ASTM A574, ensuring dimensional accuracy and mechanical consistency. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), supporting global environmental and safety regulations.