S-91259A816 1/2"-13 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Superior load-bearing capacity with 140,000 psi tensile strength and 84,000 psi shear strength for demanding industrial applications
• Exceptional wear resistance and corrosion protection thanks to the black oxide finish and Rockwell C32 hardness
• Precise assembly and alignment ensured by the Class 3A thread fit and standard shoulder fit
• Secure, non-slip installation provided by the knurled head and 5/16" hex drive
• Reliable performance in regulated environments with compliance to RoHS 3 and REACH standards
• Optimized for high-vibration applications featuring coarse UNC threading and a generous 5 1/2" shoulder length
• Guaranteed dimensional consistency meeting ASME B18.3 and ASTM A574 specifications

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in industrial applications where precision alignment and high shear strength are paramount. The 1/2"-13 UNC thread with Class 3A fit ensures secure fastening in high-vibration environments, while the 5 1/2" shoulder length provides a stable bearing surface for rotating components like gears, pulleys, and linkages. The black oxide finish enhances corrosion resistance, extending service life in harsh conditions. Its 140,000 psi tensile strength and 84,000 psi minimum shear strength make it ideal for heavy-duty shoulder fasteners in machinery, automotive, and aerospace assemblies, reducing maintenance and downtime.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit with UNC coarse threading for superior engagement. Dimensional tolerances include a shoulder diameter of 5/8" (-0.004" to -0.002") and shoulder length of 5 1/2" (-0.005" to 0.005"). It is manufactured in compliance with ASME B18.3 and ASTM A574 specifications, and is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant for environmental safety.