S-8077A856 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 industrial environments and chemical exposure.
• Enhanced durability and wear resistance from the black oxide finish, providing a protective layer against abrasion and reducing galling.
• High mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for reliable performance in demanding applications.
• Precise alignment and smooth rotation enabled by the 2" shoulder with tight tolerances, minimizing component wear and ensuring accurate assembly.
• Secure, slip-resistant installation with the knurled socket head and hex drive, allowing for high torque application and easy handling.
• Fine thread engagement with Class 3A UNF threads for superior vibration resistance and a tighter, more secure fit in critical assemblies.
• Compliance with major industry standards including ASME B18.3, RoHS 3, and REACH, ensuring quality, safety, and environmental responsibility.

Professional Applications & Engineering Value

This shoulder screw is engineered to address common industrial challenges such as misalignment, component wear, and corrosion in high-stress environments. The 316 stainless steel material provides excellent resistance to chemicals and moisture, making it suitable for marine, chemical processing, and food industry applications. The black oxide finish not only enhances corrosion protection but also reduces friction, facilitating smoother operation in moving parts like pivots, linkages, and bearing surfaces. With its fine UNF threads and precise shoulder diameter, it ensures accurate positioning and reduces the risk of loosening under vibration, offering reliable performance in machinery, automation systems, and precision equipment. This design minimizes maintenance needs and extends service life, delivering long-term engineering value for B2B clients.

Specification Summary & Compliance

This shoulder screw features a 1/4"-28 UNF thread with Class 3A fit for high precision and tight tolerances. The shoulder diameter is 5/16" with a tolerance of -0.004" to -0.002", and the shoulder length is 2" with a tolerance of -0.005" to 0.005", ensuring consistent performance. It meets ASME B18.3 specifications for dimensional accuracy and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its adherence to environmental and safety standards for industrial use.