S-91327A305 1/2"-13 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with permanent 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 5/8" shoulder diameter providing accurate component positioning and reduced wear
• High-strength performance delivering 70,000 psi tensile strength and Rockwell B55 hardness for demanding industrial applications
• Enhanced grip and torque application with knurled socket head and 5/16" hex drive for secure tool engagement and easy installation
• Reliable thread engagement through Class 3A thread fit and UNC coarse threading for consistent performance and quick assembly
• Industry compliance assurance meeting ASME B18.3 specifications and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

This 1/2"-13 UNC shoulder screw delivers exceptional engineering value in precision assembly applications where vibration resistance and accurate alignment are critical. The 18-8 stainless steel construction with passivated finish provides superior corrosion protection in manufacturing environments, while the permanent nylon patch locking technology ensures secure fastening in equipment subject to constant motion and thermal cycling. The precision Class 3A thread fit and 5/8" shoulder diameter work together to maintain exact component positioning in machinery, pivots, and rotating assemblies, reducing wear and extending service intervals. The combination of 70,000 psi tensile strength and Rockwell B55 hardness makes this socket head shoulder screw ideal for high-stress applications across automotive, aerospace, and industrial equipment sectors.

Specification Summary & Compliance

This shoulder screw features precision Class 3A thread fit with UNC coarse threading (1/2"-13) and maintains tight dimensional tolerances including shoulder diameter tolerance of -0.004" to -0.002". Manufactured in compliance with ASME B18.3 specifications, the component meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards. The nylon patch thread locker operates effectively across a temperature range of -50° to 250° F, while the mechanical properties include 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance in industrial applications.