S-91327A163 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with nylon patch thread locker maintains secure fastening in temperatures from -50° to 250°F, preventing loosening in dynamic applications.
• Exceptional corrosion resistance from 18-8 stainless steel and passivated finish ensures long-term durability in harsh industrial environments.
• High-strength construction delivers 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance under heavy loads.
• Precision thread engagement with Class 3A fit provides consistent, reliable mating with components, reducing assembly issues.
• Secure installation and removal facilitated by the knurled socket head and hex drive, offering superior grip and torque transmission.
• Accurate shoulder positioning with a 1 1/4" shoulder length and 3/8" diameter, ensuring precise alignment in assemblies like pivots and rotating parts.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This 5/16"-18 UNC shoulder screw is engineered to address common challenges in industrial settings, such as component misalignment and vibration-induced failure. Made from 18-8 stainless steel with a passivated finish, it resists corrosion and wear, extending service life in machinery, automotive, and electronics applications. The nylon patch thread locker ensures that the screw remains securely fastened even under thermal cycling and dynamic stresses, reducing maintenance needs. Its Class 3A thread fit and precise shoulder dimensions provide reliable alignment in assemblies like bearings and linkages, minimizing downtime and improving operational efficiency. Ideal for high-stress environments, this screw combines durability with compliance to meet rigorous industrial demands.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit with UNC coarse threads for robust engagement, and a shoulder diameter tolerance of -0.004" to -0.002" for precise fits. Manufactured in accordance with ASME B18.3 specifications, it ensures dimensional accuracy and performance. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it meets environmental and safety standards for industrial use.