S-8077A857 1/4"-28 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel construction, ideal for harsh environments like marine or chemical processing.
• Enhanced durability and reduced galling thanks to the Black Oxide finish, which also provides a sleek, non-reflective appearance.
• High tensile strength of 70,000 psi and shear strength of 35,000 psi for reliable performance in demanding mechanical applications.
• Precise alignment and smooth rotation enabled by the 3" shoulder with tight diameter tolerance, minimizing wear on assembled components.
• Secure, non-slip installation with a knurled socket head and 5/32" hex drive, allowing for high torque application without stripping.
• Fine 1/4"-28 UNF thread with Class 3A fit ensures vibration resistance and a tight, secure fastening in precision assemblies.
• Full compliance with ASME B18.3, RoHS 3, and REACH guarantees material safety and adherence to international industrial standards.

Professional Applications & Engineering Value

This 316 Stainless Steel shoulder screw is engineered to address critical challenges in industrial settings, such as component misalignment and corrosion-induced failure. The black oxide finish not only enhances corrosion resistance but also reduces friction during assembly, prolonging the life of both the fastener and the mating parts. Its 3" shoulder length provides a precise pivot or bearing surface, essential in machinery, automation systems, and conveyor assemblies where exact alignment is crucial. The fine UNF thread and Class 3A fit offer superior vibration resistance, making it ideal for high-stress applications in aerospace, automotive, and heavy equipment. By combining robust tensile and shear strength with a knurled socket head for secure driving, this shoulder screw delivers reliable performance in demanding environments, reducing maintenance downtime and ensuring long-term operational integrity.

Specification Summary & Compliance

This shoulder screw features a 1/4"-28 UNF fine thread with Class 3A thread fit for high precision. The shoulder diameter tolerance is -0.004" to -0.002", and shoulder length tolerance is -0.005" to 0.005", ensuring exact dimensional accuracy. It meets ASME B18.3 specifications for dimensional and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free from hazardous substances and safe for various industrial and international applications.