S-91259A807 1/2"-13 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional strength and durability with 140,000 psi tensile strength and 84,000 psi shear strength for reliable performance in demanding applications.
• Precise thread engagement thanks to Class 3A fit and 1/2"-13 UNC coarse threads, ensuring secure fastening and vibration resistance.
• Superior wear and corrosion resistance from the Black Oxide finish and Rockwell C32 hardness, extending service life in harsh industrial environments.
• Secure installation and removal with a 5/16" hex drive and knurled head, providing excellent grip and torque transmission.
• Accurate alignment and spacing due to the 3 1/4" shoulder with tight diameter and length tolerances, ideal for pivot points and rotating assemblies.
• Compliance with industry standards including ASME B18.3 and ASTM A574, guaranteeing consistent quality and interchangeability.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance, meeting global regulatory requirements.

Professional Applications & Engineering Value

This Alloy Steel Shoulder Screw is engineered to address critical challenges in mechanical assemblies where precision alignment, high load-bearing capacity, and durability are paramount. The 1/2"-13 UNC coarse thread with Class 3A fit ensures rapid assembly and reliable clamping force, reducing the risk of loosening under vibration. The Black Oxide finish provides a protective layer against corrosion and wear, making it suitable for automotive, machinery, and heavy equipment applications. The generous 3 1/4" shoulder length acts as a precise shaft for rotating components like gears and pulleys, minimizing misalignment and wear. With a Rockwell C32 hardness and high tensile strength, it withstands extreme operational stresses, offering long-term reliability and reduced maintenance costs in industrial settings.

Specification Summary & Compliance

This shoulder screw features a 1/2"-13 UNC thread with Class 3A fit for precise thread engagement, and a shoulder diameter of 5/8" with tight tolerances (-0.004" to -0.002") for accurate alignment. It is manufactured in accordance with ASME B18.3 and ASTM A574 specifications, ensuring dimensional consistency and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its adherence to environmental and safety standards.