S-91327A134 1/4"-20 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
• Exceptional corrosion resistance through 18-8 stainless steel construction with passivated finish, ensuring long-term reliability in harsh environments
• Precise shoulder positioning with controlled shoulder diameter and length tolerances for accurate component alignment and spacing
• High-strength performance delivering 70,000 psi tensile strength and Rockwell B55 hardness for demanding industrial applications
• Superior thread integrity with Class 3A thread fit providing tighter tolerances for more reliable engagement and load distribution
• Enhanced grip and torque application through knurled socket head with 5/32" hex drive, allowing for secure tool engagement during installation
• Industry compliance assurance meeting ASME B18.3 specifications while being RoHS 3 and REACH compliant for global regulatory requirements

Professional Applications & Engineering Value

This 1/4"-20 UNC shoulder screw with nylon patch locking addresses critical engineering challenges in precision assembly applications. The 18-8 stainless steel construction with passivated finish provides exceptional corrosion resistance for harsh industrial environments, while the precisely controlled shoulder diameter and length ensure accurate component alignment in machinery, automation systems, and precision instruments. The integrated nylon patch thread locker effectively counters vibration-induced loosening in dynamic applications from robotics to transportation equipment. With Class 3A thread fit and knurled socket head design, this shoulder screw delivers reliable performance in applications requiring repeated disassembly and reassembly, making it ideal for manufacturing fixtures, bearing retention, and linkage systems where positional accuracy and vibration resistance are paramount.

Specification Summary & Compliance

This precision shoulder screw features 1/4"-20 UNC coarse threads with Class 3A thread fit for superior engagement accuracy. The shoulder diameter maintains tight tolerances of -0.004" to -0.002" with shoulder length tolerance of -0.005" to 0.005" for precise component positioning. Manufactured in compliance with ASME B18.3 specifications, this fastener meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring global compliance for industrial applications requiring high reliability and environmental responsibility.