S-91327A304 1/2"-13 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with integrated nylon patch that maintains secure fastening from -50° to 250°F, preventing loosening in dynamic applications
• Superior corrosion resistance through 18-8 stainless steel construction and passivated finish for extended service life in harsh environments
• Precision alignment capability with Class 3A thread fit and standard shoulder fit ensuring accurate component positioning
• Enhanced torque transmission via 5/16" hex drive and knurled head design for secure tool engagement and reduced slippage
• High mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for demanding industrial applications
• Reliable dimensional stability with tight shoulder diameter tolerance (-0.004" to -0.002") ensuring consistent performance in precision assemblies
• Industry compliance assurance meeting ASME B18.3 standards and environmental regulations for global manufacturing requirements

Professional Applications & Engineering Value

This 1/2"-13 UNC shoulder screw delivers exceptional engineering value in applications requiring precise component alignment and vibration resistance. The 18-8 stainless steel construction with passivated finish provides superior corrosion resistance for machinery operating in humid or chemical environments. The integrated nylon patch thread locker eliminates the need for separate locking components, streamlining assembly while maintaining secure fastening across a wide temperature range (-50° to 250°F). The knurled head and 5/16" hex drive ensure positive tool engagement during installation, reducing the risk of fastener damage in high-torque applications. These shoulder screws are particularly valuable in precision equipment, automation systems, and rotating assemblies where the shoulder provides accurate bearing surfaces and the Class 3A thread fit ensures consistent clamping force.

Specification Summary & Compliance

This precision shoulder screw features 1/2"-13 UNC coarse threads with Class 3A fit for superior thread engagement. The shoulder maintains tight diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005" for precise component alignment. Manufactured to ASME B18.3 specifications with 70,000 psi tensile strength and Rockwell B55 hardness. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards for global industrial applications.