S-91259A818 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 demanding applications.
• Superior corrosion resistance due to the black oxide finish, extending service life in harsh industrial environments.
• Precise alignment and smooth rotation enabled by the 6" shoulder with tight diameter tolerance for reduced wear and vibration.
• High thread reliability with Class 3A fit and coarse UNC thread for quick assembly and secure fastening under stress.
• Easy installation and removal using the 5/16" hex drive and knurled head for improved grip and torque application.
• Enhanced durability from Rockwell C32 hardness alloy steel, resisting deformation under heavy loads.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH for safety and environmental responsibility.

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical challenges in machinery and equipment assembly, where precise component alignment and high-strength fastening are essential. The alloy steel construction and black oxide finish provide excellent resistance to corrosion and wear, making it ideal for automotive, aerospace, and heavy industrial applications. The 1/2"-13 UNC coarse thread ensures rapid installation and robust holding power, while the 6" shoulder length acts as a dependable pivot or spacer, reducing friction and maintaining accuracy in rotating parts. By integrating a socket head with hex drive, it simplifies maintenance in confined spaces, enhancing operational efficiency and reducing downtime.

Specification Summary & Compliance

This shoulder screw features a 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" to ensure consistent performance. It adheres to ASME B18.3 specifications and is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, confirming its suitability for global industrial use without hazardous substances.