S-91259A855 5/8"-11 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Extended service life and corrosion resistance with a durable black oxide finish that protects against rust in demanding industrial environments.
• Superior load-bearing capacity and joint integrity from high-strength alloy steel, offering a tensile strength of 140,000 psi and a shear strength of 84,000 psi.
• Precise component alignment and reduced wear thanks to the precision-ground shoulder with controlled diameter and length tolerances.
• Reliable, vibration-resistant assembly ensured by the Class 3A thread fit and coarse UNC thread for secure fastening in high-stress applications.
• Easy installation and removal with high torque capability via the knurled socket head and 3/8" hex drive, preventing tool slippage.
• Consistent performance and interchangeability guaranteed by compliance with the ASME B18.3 standard for dimensional accuracy.
• Safe for use in regulated industries with full compliance to RoHS 3 and REACH environmental and safety standards.

Professional Applications & Engineering Value

This 5/8"-11 UNC shoulder screw is engineered to address critical alignment and high-stress challenges in industrial machinery and precision assemblies. The alloy steel construction, hardened to Rockwell C32, provides exceptional resistance to deformation under heavy loads, while the black oxide finish enhances corrosion resistance, extending component life in harsh environments. The precision shoulder diameter and length ensure accurate positioning of moving parts, such as in gears, pulleys, and linkages, minimizing misalignment and wear. With its coarse UNC thread and Class 3A fit, it offers reliable fastening that withstands vibrations, making it ideal for automotive, aerospace, and heavy equipment applications where durability and precision are paramount.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit for precise engagement, with a thread size of 5/8"-11 UNC and a shoulder diameter tolerance of -0.004" to -0.002". It is manufactured in accordance with ASME B18.3 specifications and meets ASTM A574 material standards. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and safe for various industrial uses.