S-91259A845 5/8"-11 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Load-Bearing Capacity: With a tensile strength of 140,000 psi and shear strength of 84,000 psi, this screw reliably handles high-stress applications without failure.
• Precision Alignment and Reduced Wear: The 3/4" shoulder diameter with tight tolerances ensures accurate component positioning, minimizing misalignment and extending equipment life.
• Corrosion Resistance and Durability: The black oxide finish provides a protective layer against rust and wear, suitable for harsh industrial environments.
• Secure and Efficient Installation: The knurled socket head with 3/8" hex drive offers superior grip and torque transmission, reducing slippage during assembly.
• Industry-Standard Compliance: Meets ASME B18.3 specifications and ASTM A574, ensuring consistent quality and interchangeability in professional settings.
• High Thread Reliability: Class 3A thread fit with UNC coarse threads delivers secure fastening and resistance to vibration loosening in dynamic applications.
• Environmental and Safety Compliance: RoHS 3 and REACH compliant, making it safe for use in regulated industries without hazardous substances.

Professional Applications & Engineering Value

This 5/8"-11 UNC shoulder screw is engineered to address critical challenges in industrial machinery, automation systems, and precision equipment. The alloy steel construction, hardened to Rockwell C32, ensures it withstands heavy loads and repetitive stress without deformation. The black oxide finish enhances corrosion resistance, ideal for environments exposed to moisture or chemicals. With a 2-1/2" shoulder length and precise 3/4" shoulder diameter, it provides stable pivot points and accurate alignment in assemblies, reducing wear on moving parts. The coarse UNC threads and Class 3A fit offer quick installation and reliable holding power, minimizing maintenance downtime. Commonly used in robotic arms, conveyor systems, and fixturing applications, this screw delivers consistent performance where precision and strength are paramount.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 standards and ASTM A574 material specifications, ensuring dimensional accuracy with a Class 3A thread fit for tight tolerances. Key measurements include a shoulder diameter of 3/4" (tolerance: -0.004" to -0.002") and shoulder length of 2-1/2" (tolerance: -0.005" to 0.005"). It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing environmental safety and suitability for global industrial use.