S-8077A651 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel construction and Black Oxide finish, ideal for harsh industrial environments.
• Exceptional mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for reliable load-bearing applications.
• Precise shoulder positioning with controlled shoulder diameter and length tolerances, ensuring accurate alignment in assemblies.
• High-accuracy Class 3A thread fit for secure, vibration-resistant fastening in demanding mechanical systems.
• Easy installation and removal with a knurled socket head and hex drive, providing superior grip and torque transmission.
• Compliance with major industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and regulatory adherence.
• Durable coarse UNC threads that resist stripping and allow for quick assembly in high-vibration settings.

Professional Applications & Engineering Value

This 5/16"-18 UNC shoulder screw is engineered to address critical challenges in precision machinery, automation, and heavy-duty equipment. The 316 Stainless Steel material, combined with a Black Oxide finish, provides excellent resistance to corrosion, chemicals, and oxidation, making it suitable for marine, chemical processing, and outdoor applications. The Class 3A thread fit and precisely machined shoulder (3/8" diameter, 1/8" length) ensure minimal play and exact component alignment, reducing wear and maintenance costs. With a Rockwell B79 hardness and high tensile strength, it supports robust performance in assemblies subject to dynamic loads and vibrations. The socket head with knurled texture and hex drive allows for efficient installation in confined spaces, enhancing productivity in industrial fastener systems.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with a Class 3A thread fit for superior precision. Thread details include 5/16"-18 UNC coarse threads and right-hand direction. Shoulder dimensions are tightly controlled: diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005". The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material restrictions are met.