S-8077A333 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh industrial environments and extended service life.
• Exceptional mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for reliable performance under high-stress conditions.
• Precise alignment and smooth rotation ensured by the 2" long shoulder with tight diameter and length tolerances for consistent assembly.
• Enhanced wear resistance and reduced galling from the black oxide finish, providing a durable protective layer.
• Secure, non-slip fastening with a knurled socket head and 1/4" hex drive, allowing for high-torque application without stripping.
• Reliable thread engagement with Class 3A fit and coarse 5/16"-18 UNC threads for quick assembly and vibration resistance.
• Full regulatory compliance with ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental standards are met.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in precision machinery and industrial assemblies. The black oxide finish on the socket head shoulder screw enhances corrosion resistance, reducing maintenance in humid or chemically aggressive settings. Its 2" shoulder length provides a stable pivot or spacer, minimizing misalignment in rotating parts like bearings, pulleys, and linkages. The coarse 5/16"-18 UNC thread and Class 3A fit ensure rapid installation and secure hold, resisting loosening under dynamic loads. With a Rockwell B79 hardness and high tensile strength, it withstands repetitive stress in automotive, aerospace, and heavy equipment applications, delivering long-term reliability and reduced downtime.

Specification Summary & Compliance

This shoulder screw features precision dimensions, including a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005", ensuring consistent fit. Threads adhere to UNC coarse standards with a Class 3A fit for superior engagement. Manufactured in compliance with ASME B18.3 specifications, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming environmental and safety adherence for industrial use.