S-91264A718 1/2"-13 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with integrated nylon pellet thread locker maintains secure fastening in temperatures from -50° to 250°F, reducing maintenance needs in dynamic applications.
• Exceptional load-bearing capacity from 140,000 PSI tensile strength and 84,000 PSI shear strength ensures reliable performance under heavy mechanical stress.
• Precision alignment and smooth rotation enabled by the 1 3/4" shoulder with tight diameter tolerance, minimizing wear in pivoting or sliding assemblies.
• Easy installation and removal with 5/16" hex drive and knurled head design, providing superior grip and torque application without specialized tools.
• Corrosion resistance and durability from black oxide finish on alloy steel, extending service life in harsh industrial environments.
• Accurate thread engagement with Class 3A UNC coarse threads ensures consistent clamping force and reduces cross-threading risks.
• Compliance with industry standards including ASME B18.3 and ASTM A574 guarantees interchangeability and quality assurance for engineering projects.

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical alignment and vibration challenges in precision machinery. The alloy steel construction and black oxide finish provide robust corrosion resistance, ideal for automotive, aerospace, and heavy equipment applications where exposure to oils and moisture is common. The 1 3/4" shoulder length acts as a precise shaft for rotating components like gears and bearings, eliminating the need for additional bushings and reducing assembly complexity. Integrated nylon pellet thread locker secures the 1/2"-13 UNC coarse threads against loosening under cyclic loads, enhancing safety in conveyor systems or robotic arms. By combining high tensile strength with exacting tolerances, this screw minimizes downtime and improves operational reliability in demanding industrial settings.

Specification Summary & Compliance

This shoulder screw features Class 3A thread fit for precise engagement, with shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005" ensuring consistent performance. Manufactured to ASME B18.3 and ASTM A574 specifications, it guarantees dimensional accuracy and mechanical properties. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for global industrial use.