S-91264A150 3/8"-16 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with nylon pellet thread locker maintains secure fastening in temperatures from -50° to 250°F, reducing maintenance needs in dynamic environments.
• Exceptional strength and durability from alloy steel construction delivers 140,000 psi tensile strength and 84,000 psi shear strength for heavy-duty applications.
• Precise alignment and smooth rotation ensured by the 1/2" shoulder diameter with tight tolerances, minimizing wear on connected components.
• Reliable thread engagement with Class 3A fit and 3/8"-16 UNC coarse threads provides consistent clamping force and easy assembly.
• Corrosion-resistant black oxide finish extends service life by protecting against rust in industrial settings.
• Secure grip and easy installation thanks to the knurled socket head and 1/4" hex drive, allowing for high-torque applications without slippage.
• Compliance with industry standards including ASME B18.3 and ASTM A574 ensures consistent quality and interoperability.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in precision machinery and assembly lines, where misalignment and vibrational loosening can lead to equipment failure. The 1/2" shoulder diameter with controlled tolerances acts as a precise pivot or spacer, reducing friction and wear in rotating assemblies like conveyor systems, robotic arms, and automotive fixtures. The Class 3A thread fit and coarse UNC threads ensure rapid, reliable fastening even in high-vibration environments, while the integrated nylon pellet thread locker secures joints without requiring additional adhesives. Paired with a black oxide finish, it resists corrosion in humid or chemically exposed settings, making it ideal for industrial automation, precision manufacturing, and heavy equipment applications where durability and repeatability are paramount.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit with 3/8"-16 UNC coarse threads, ensuring high precision and interchangeability. The shoulder diameter is manufactured to a tolerance of -0.004" to -0.002", and the shoulder length to -0.005" to 0.005", adhering to strict dimensional standards. It complies with ASME B18.3 and ASTM A574 specifications for material and design, and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming its suitability for global industrial use without hazardous substances.