S-97768A358 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Corrosion Resistance: Black oxide finish on 18-8 stainless steel provides superior protection against rust and environmental degradation, extending service life in harsh industrial settings.
• High Tensile and Shear Strength: With 70,000 psi tensile and 35,000 psi minimum shear strength, this screw ensures reliable, high-load fastening for demanding applications.
• Precision Thread Fit: Class 3A UNC coarse threads offer excellent engagement and vibration resistance, reducing the risk of loosening in dynamic assemblies.
• Secure and Easy Installation: Hex socket drive with 3/16" size allows for high-torque application and prevents stripping, while the knurled head improves grip during manual handling.
• Accurate Shoulder Positioning: Tight tolerances on shoulder diameter and length (-0.004" to -0.002" and -0.005" to 0.005", respectively) ensure precise alignment and spacing in machinery and fixtures.
• Durable Material Hardness: Rockwell B55 hardness provides optimal balance between strength and machinability, resisting wear and deformation under stress.
• Compliance and Safety Assurance: Meets ASME B18.3 specifications and is RoHS 3 and REACH compliant, ensuring environmental safety and regulatory adherence for global supply chains.

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical alignment and load-bearing challenges in industrial assemblies. The 18-8 stainless steel construction, combined with a black oxide finish, offers exceptional corrosion resistance, making it ideal for applications in humid or chemically aggressive environments like automotive, aerospace, and manufacturing equipment. The UNC coarse threading and Class 3A fit ensure quick assembly and reliable retention, reducing downtime in high-vibration settings. The precise shoulder diameter and length facilitate accurate component positioning in rotating parts, jigs, and pivoting mechanisms, while the hex socket drive enables efficient installation in confined spaces. By integrating high tensile and shear strength with robust material properties, this screw minimizes failure risks and enhances the longevity of mechanical systems, supporting efficient B2B procurement for precision-driven industries.

Specification Summary & Compliance

This shoulder screw adheres to strict dimensional standards, including a Class 3A thread fit for precise UNC coarse threading and tight shoulder tolerances (diameter: -0.004" to -0.002"; length: -0.005" to 0.005"). It conforms to ASME B18.3 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity for industrial use.