S-91259A808 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 shear strength for reliable performance in high-stress applications
• Superior corrosion resistance provided by the black oxide finish, extending service life in demanding industrial environments
• Precision thread engagement with Class 3A fit ensuring secure fastening and vibration resistance in critical assemblies
• Enhanced grip and torque application through the knurled socket head design with 5/16" hex drive for easy installation
• Accurate component alignment facilitated by the 3 1/2" shoulder length with tight diameter tolerance for precise machinery positioning
• Industry-standard compatibility with UNC coarse threads and ASME B18.3 specifications for seamless integration into existing systems
• Environmental compliance assurance meeting RoHS 3 and REACH regulations for safe use across global markets

Professional Applications & Engineering Value

This alloy steel shoulder screw delivers critical engineering solutions for industrial machinery and precision equipment. The 3 1/2" shoulder length with controlled diameter tolerance provides exact bearing surfaces for rotating components, eliminating misalignment issues in conveyor systems, automation equipment, and gear assemblies. The black oxide finish protects against rust and corrosion in harsh operating conditions, while the Class 3A thread fit maintains clamping force under vibration. With UNC coarse threads and 140,000 psi tensile strength, this socket head shoulder screw withstands extreme mechanical stresses in heavy-duty applications, from manufacturing fixtures to automotive assemblies, ensuring long-term reliability and reduced maintenance costs.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit precision and UNC coarse thread profile. The shoulder diameter maintains -0.004" to -0.002" tolerance while shoulder length holds -0.005" to 0.005" tolerance. Complies with ASME B18.3 specifications and manufactured to ASTM A574 standards. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across industrial sectors.