S-8077A666 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 added protection against rust and galling.
• Precise alignment and smooth rotation due to the standard shoulder fit and knurled head, reducing assembly time and improving component stability.
• High load-bearing capacity with 70,000 psi tensile strength and 35,000 psi shear strength, ensuring reliable performance under stress.
• Secure, vibration-resistant fastening from the Class 3A UNF fine thread, offering a tighter fit and reduced loosening in dynamic applications.
• Easy installation and removal using a standard hex drive (3/16"), facilitated by the socket head design for efficient maintenance.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, guaranteeing safety and regulatory adherence for global supply chains.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw with a black oxide finish is engineered to address critical challenges in precision assembly and harsh operating conditions. The UNF fine threading (1/4"-28) and Class 3A thread fit ensure minimal backlash and secure fastening in high-vibration environments like robotics, automotive systems, and machinery. The knurled head enhances grip during manual adjustments, while the standard shoulder provides accurate spacing and alignment for rotating parts, reducing wear and maintenance costs. Ideal for industrial fasteners in corrosive settings, it combines high tensile strength with regulatory compliance, supporting efficient B2B procurement for engineering and manufacturing sectors.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with precise dimensions including a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005". The Class 3A thread fit and UNF fine thread type ensure high accuracy, while material properties like Rockwell B79 hardness support durability. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), meeting environmental and safety standards for industrial use.