S-91327A295 8-32 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Secure Vibration Resistance: Integrated nylon patch thread locker prevents loosening under dynamic loads, ensuring reliable performance in high-vibration industrial environments.
• Exceptional Corrosion Resistance: Made from 18-8 Stainless Steel with a passivated finish for superior protection against rust and corrosion in harsh conditions.
• High Mechanical Strength: Offers a 70,000 psi tensile strength and Rockwell B55 hardness for robust, durable connections that withstand heavy loads.
• Precision Fit and Alignment: Features a Class 3A thread fit and standardized shoulder for accurate component positioning and reduced assembly play.
• Wide Temperature Tolerance: The nylon patch locker remains effective from -50° to 250° F, making it suitable for applications with thermal cycling.
• Easy Installation and Removal: Hex socket drive allows for high-torque application with standard tools, speeding up assembly and maintenance processes.
• Industry Standard Compliance: Manufactured to meet ASME B18.3 specifications, ensuring interchangeability and reliability in professional applications.

Professional Applications & Engineering Value

This stainless steel shoulder screw is engineered to address critical challenges in precision assembly and motion control systems. The 8-32 UNC coarse thread and 3/16" shoulder length provide a stable pivot point and precise axial location for components like gears, bearings, and linkages, minimizing misalignment and wear. The nylon patch thread locking feature is essential for applications subject to vibration, such as in automotive, robotics, and conveyor systems, where it prevents back-off without the need for separate locking hardware. The combination of 18-8 stainless steel material and passivated finish ensures long-term durability in corrosive or wash-down environments, common in food processing, marine, and outdoor equipment. By integrating the shoulder and locking functions, this screw simplifies BOMs and reduces assembly time, delivering consistent performance and reliability for demanding industrial shoulder screw applications.

Specification Summary & Compliance

This shoulder screw adheres to precise dimensional standards, including a Class 3A thread fit for tight tolerances and the UNC coarse thread profile per ASME B18.3. The shoulder diameter and length are manufactured within specified tolerances (e.g., shoulder diameter: -0.004" to -0.002") to ensure consistent performance. It is fully compliant with ASME B18.3 for mechanical and dimensional requirements, RoHS 3 (2015/863/EU) for hazardous substance restrictions, and REACH (EC 1907/2006) for chemical safety, making it suitable for global supply chains and regulated industries.