S-8077A334 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 chemical exposure
• Enhanced durability and wear resistance from the black oxide finish, providing long-lasting performance and reduced maintenance
• Precise alignment and smooth rotation ensured by the 3" shoulder with tight diameter tolerance for reliable bearing surfaces
• High-strength performance with 70,000 psi tensile strength and 35,000 psi shear strength, supporting heavy-duty applications
• Secure, non-slip installation thanks to the knurled socket head and 1/4" hex drive, allowing for high torque application
• Consistent, reliable threading with Class 3A fit and 5/16"-18 UNC coarse thread, ensuring easy assembly and vibration resistance
• Compliance with industry standards including ASME B18.3, RoHS, and REACH, guaranteeing quality and environmental safety

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw with black oxide finish is engineered to address critical challenges in precision machinery and industrial assembly. The 3" shoulder length provides an exact pivot or bearing surface, minimizing misalignment in rotating components like gears, pulleys, and linkages. The Class 3A thread fit and coarse UNC thread enhance assembly speed and resistance to loosening under vibration, common in automotive and manufacturing equipment. With high tensile and shear strength, it supports dynamic loads without failure, while the knurled socket head ensures secure tool engagement during installation. Ideal for applications requiring corrosion resistance and dimensional stability, this screw delivers long-term reliability in demanding environments.

Specification Summary & Compliance

This shoulder screw features precise dimensions including a shoulder diameter of 1/2" with tolerance of -0.004" to -0.002" and shoulder length of 3" with tolerance of -0.005" to 0.005". Thread specifications include 5/16"-18 UNC with Class 3A thread fit for high precision. It complies with ASME B18.3 manufacturing standards and is RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, ensuring adherence to environmental and safety regulations. Hardness is Rockwell B79, supporting consistent performance in industrial applications.