S-8077A822 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel construction and Black Oxide finish, ideal for harsh industrial environments.
• Precise alignment and reduced wear thanks to the standard shoulder fit and Class 3A thread tolerance for secure, vibration-resistant assemblies.
• High mechanical strength with 70,000 psi tensile and 35,000 psi minimum shear strength, ensuring reliable performance under heavy loads.
• Easy installation and removal using a standard 5/32" hex drive and knurled head for improved grip and torque application.
• Durable and long-lasting with Rockwell B79 hardness, maintaining integrity in repetitive or high-stress applications.
• Broad compatibility with 1/4"-20 UNC coarse threads and 3 1/4" shoulder length, fitting standard industrial components seamlessly.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This shoulder screw is engineered to address common industrial challenges such as misalignment, corrosion, and mechanical failure. The 316 Stainless Steel material, combined with a Black Oxide finish, provides excellent resistance to rust and chemicals, making it suitable for marine, chemical processing, and outdoor equipment. The UNC coarse thread and Class 3A fit ensure quick assembly and high clamping force, reducing the risk of loosening in vibrating machinery. With a precise shoulder diameter and length, it acts as a pivot or spacer in rotating assemblies, minimizing wear on connected parts. Ideal for use in precision machinery, automotive systems, and conveyor equipment, this fastener enhances operational reliability and reduces maintenance costs.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC thread with Class 3A tolerance for precise fit, and a shoulder diameter of 5/16" with tight tolerances (-0.004" to -0.002") to ensure accurate alignment. Manufacturing adheres to ASME B18.3 specifications, guaranteeing dimensional consistency and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally safe and sustainable industrial practices.