S-91327A139 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking: Integrated nylon patch thread locker ensures secure fastening in high-vibration environments, maintaining integrity from -50° to 250° F.
• Exceptional corrosion resistance: Made from 18-8 stainless steel with a passivated finish for long-lasting durability in harsh industrial conditions.
• High tensile strength: Withstands up to 70,000 psi, providing reliable performance in demanding mechanical assemblies.
• Precision thread fit: Class 3A thread tolerance ensures accurate, consistent engagement and reduces the risk of cross-threading.
• Easy installation and removal: Hex socket drive with knurled head allows for secure tool grip and efficient torque application.
• Standardized dimensions: Complies with ASME B18.3 specifications, ensuring interchangeability and compatibility in various applications.
• Environmental compliance: Meets RoHS 3 and REACH regulations, making it suitable for global supply chains and sensitive industries.

Professional Applications & Engineering Value

This 1/4"-20 UNC shoulder screw is engineered to address common industrial challenges such as component misalignment, vibration-induced loosening, and corrosion. The 18-8 stainless steel construction, combined with a passivated finish, offers superior resistance to rust and chemical exposure, ideal for machinery, automotive, and electronics assemblies. The integrated nylon patch thread locker provides reliable vibration resistance without requiring additional adhesives, simplifying maintenance. With a knurled head and hex drive, it ensures easy handling in tight spaces, while the precise shoulder diameter and length facilitate accurate positioning of moving parts. These features make it a top choice for precision fastening in robotics, conveyor systems, and industrial equipment, enhancing operational reliability and reducing downtime.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit with UNC coarse threading for robust engagement. Dimensions include a 1/4"-20 thread size, 7/16" thread length, and precise shoulder diameter (5/16") and length (3/4") with tight tolerances. It is manufactured in accordance with ASME B18.3 standards and complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and industry acceptance.