S-91264A544 1/4"-20 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with integrated nylon pellet that maintains secure fastening from -50° to 250°F, preventing loosening in demanding applications
• Exceptional strength and durability from alloy steel construction with 140,000 psi tensile strength and 84,000 psi shear strength for heavy-duty use
• Precise shoulder alignment with controlled diameter tolerance (-0.004" to -0.002") ensuring accurate component positioning
• Superior corrosion protection through black oxide finish that extends service life in harsh industrial environments
• Reliable thread engagement with Class 3A thread fit providing consistent, high-precision fastening performance
• Easy installation and removal via 5/32" hex drive socket with knurled head for improved grip during tool operation
• Industry-standard compliance meeting ASME B18.3 specifications for guaranteed quality and interchangeability

Professional Applications & Engineering Value

This alloy steel shoulder screw with black oxide finish addresses critical industrial fastening challenges where vibration resistance and precise alignment are paramount. The integrated nylon pellet thread locker provides reliable vibration damping across a wide temperature range (-50° to 250°F), eliminating the need for separate locking compounds in applications such as rotating machinery, precision assemblies, and automated equipment. The Class 3A thread fit ensures consistent engagement in UNC coarse threads, while the precisely controlled shoulder diameter maintains accurate component positioning in linkages, bearings, and pivoting mechanisms. With Rockwell C32 hardness and high tensile strength, this socket head shoulder screw delivers long-term reliability in demanding industrial environments where failure is not an option.

Specification Summary & Compliance

This precision shoulder screw features 1/4"-20 UNC coarse threads with Class 3A thread fit for superior engagement. Manufacturing complies with ASME B18.3 specifications where applicable per ASTM A574. The component meets RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) requirements as of 06/14/2023. Critical dimensions include shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005" for precision applications.