S-91259A792 1/2"-13 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 minimum shear strength, this shoulder screw reliably handles high-stress applications without failure.
• Precision Shoulder Alignment: The 5/8" shoulder diameter with tight tolerances (-0.004" to -0.002") ensures accurate component positioning and smooth rotational movement.
• Superior Thread Engagement: Class 3A UNC coarse threads provide maximum holding power and vibration resistance in demanding industrial environments.
• Enhanced Durability & Corrosion Resistance: Black oxide finish on alloy steel construction offers superior protection against wear and environmental factors.
• Secure Installation & Removal: Knurled head with 5/16" hex drive socket ensures positive grip and prevents tool slippage during torque application.
• Industry Compliance Assurance: Meets ASME B18.3 specifications while being RoHS 3 and REACH compliant for global regulatory acceptance.
• Optimized Mechanical Performance: Rockwell C32 hardness combined with precise shoulder length tolerances delivers consistent performance in repetitive assembly operations.

Professional Applications & Engineering Value

This heavy-duty shoulder screw delivers critical engineering solutions for precision machinery and industrial equipment where alignment accuracy and load distribution are paramount. The alloy steel construction with black oxide finish provides exceptional durability in harsh operating environments, while the Class 3A UNC coarse threads ensure secure fastening in high-vibration applications. The precisely machined shoulder with tight diameter and length tolerances enables exact component positioning in rotating assemblies, bearing mounts, and precision linkages. The knurled socket head with hex drive design facilitates secure tool engagement, reducing installation time and preventing damage in maintenance-intensive operations. These features make it ideal for automotive manufacturing, industrial robotics, conveyor systems, and heavy machinery where reliability and precision are non-negotiable.

Specification Summary & Compliance

This shoulder screw maintains Class 3A thread fit per UNC standards with precise shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005". Manufactured to ASME B18.3 specifications using ASTM A574 alloy steel, it ensures consistent dimensional accuracy and mechanical performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting international environmental and safety standards for industrial applications.