S-8077A646 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.
• Exceptional mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for reliable performance in heavy-duty applications.
• Precise thread engagement with Class 3A fit and UNC coarse threads ensuring secure, vibration-resistant fastening.
• Easy installation and removal thanks to the hex socket drive and knurled head for enhanced grip and torque application.
• Accurate alignment and spacing provided by the precisely machined shoulder with tight diameter and length tolerances.
• Broad regulatory compliance meeting ASME B18.3 standards, RoHS 3, and REACH for safe, global industrial use.
• Durable and long-lasting with Rockwell B79 hardness, reducing wear and maintenance needs over time.

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical challenges in precision machinery, automation systems, and heavy-duty equipment. The 316 Stainless Steel material, combined with a Black Oxide finish, provides excellent resistance to corrosion and oxidation, making it suitable for environments exposed to moisture, chemicals, or extreme temperatures. The UNC coarse threads and Class 3A thread fit ensure quick assembly and reliable holding power, reducing the risk of loosening under vibration. The knurled head and hex socket drive allow for easy handling and high-torque installation, while the precisely toleranced shoulder enables accurate component alignment in applications like bearings, pulleys, and linkages. This screw delivers consistent performance, minimizes downtime, and supports efficient production in industries such as automotive, aerospace, and manufacturing.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC thread with Class 3A fit for precise engagement, and a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005" for accurate assembly. It is manufactured in compliance with ASME B18.3 specifications and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulatory requirements, ensuring environmental safety and reliability in industrial applications.