S-97768A391 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced corrosion resistance with 18-8 stainless steel and black oxide finish for reliable performance in harsh environments
• Precise alignment and reduced wear thanks to the 3" shoulder length with tight tolerances for stable component positioning
• Superior load-bearing capacity with 70,000 psi tensile strength and 35,000 psi minimum shear strength for demanding applications
• Secure installation and removal using the hex drive socket head with knurled texture for improved grip
• Consistent thread engagement with Class 3A fit and UNC coarse threading for vibration resistance and quick assembly
• Durable mechanical properties from Rockwell B55 hardness, ensuring long-term reliability under stress
• Compliance with industry standards including ASME B18.3, RoHS, and REACH for safe, regulated use

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical alignment and durability challenges in industrial settings. The 18-8 stainless steel construction, combined with a black oxide finish, provides excellent corrosion resistance, making it ideal for machinery, automotive assemblies, and electronic enclosures exposed to moisture or chemicals. The 3" shoulder length with precise tolerances ensures accurate spacing and reduces wear on moving parts, while the UNC coarse threads and Class 3A fit offer reliable fastening in high-vibration environments. The socket head with hex drive and knurled texture allows for easy installation in tight spaces, enhancing efficiency in production lines and maintenance tasks. By meeting ASME B18.3 specifications, this screw delivers consistent performance for precision engineering applications.

Specification Summary & Compliance

This shoulder screw features a 5/16"-18 UNC thread with Class 3A fit for precise tolerance, a shoulder diameter of 3/8" with tolerance from -0.004" to -0.002", and a shoulder length of 3" with tolerance from -0.005" to 0.005". It complies with ASME B18.3 manufacturing standards and environmental regulations including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring safety and sustainability in industrial use.