S-97768A393 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction and black oxide finish, ideal for harsh industrial environments.
• Precise component alignment enabled by the 3 1/4" shoulder length with tight tolerances, ensuring accurate assembly and reduced wear.
• Superior load-bearing capacity from 70,000 psi tensile strength and 35,000 psi minimum shear strength, providing reliable performance in high-stress applications.
• Secure, non-slip fastening with a knurled socket head and 3/16" hex drive, allowing for high torque application and easy installation.
• Consistent, reliable threading with Class 3A fit and 5/16"-18 UNC coarse threads, ensuring strong engagement and vibration resistance.
• Enhanced durability and hardness with Rockwell B55 rating, offering long service life and resistance to deformation.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, guaranteeing quality and environmental safety for professional use.

Professional Applications & Engineering Value

This shoulder screw is engineered to solve critical alignment and durability challenges in mechanical assemblies. The 18-8 stainless steel material combined with a black oxide finish provides excellent resistance to corrosion and oxidation, making it suitable for automotive, aerospace, and heavy machinery applications where exposure to moisture and chemicals is common. The 3 1/4" shoulder length acts as a precise pivot or spacer, reducing misalignment and wear in rotating parts like gears and pulleys. With a Class 3A thread fit and UNC coarse threads, it ensures quick assembly and reliable performance under dynamic loads, minimizing maintenance downtime and enhancing operational efficiency in industrial fastening systems.

Specification Summary & Compliance

This shoulder screw features precise dimensions, including a shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005", ensuring high accuracy for Class 3A thread fit and consistent performance. It adheres to ASME B18.3 standards for dimensional and mechanical requirements, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety and environmental responsibility in global markets.