S-8077A647 1/4"-20 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 a protective layer against abrasion and galling.
• High-strength performance with 70,000 psi tensile strength and 35,000 psi shear strength, ensuring reliable load-bearing in demanding applications.
• Precise alignment and smooth rotation due to the precision-machined shoulder with controlled diameter and length tolerances.
• Secure, non-slip fastening enabled by the knurled head and hex socket drive, allowing for high-torque installation without stripping.
• Consistent, reliable thread engagement with Class 3A thread fit and coarse UNC threads, facilitating quick assembly and vibration resistance.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring quality and environmental safety for global supply chains.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in precision machinery and assembly. The black oxide finish not only enhances corrosion resistance but also reduces friction, preventing seizing in high-cycle applications. Its 1/4"-20 UNC coarse thread and Class 3A thread fit ensure rapid, secure fastening in components like rotating shafts, linkages, and bearing mounts, minimizing downtime. The precisely machined shoulder provides a stable pivot point, maintaining alignment in automated systems and reducing wear on mating parts. Ideal for industrial equipment, robotics, and conveyor systems, this screw delivers long-term reliability under heavy loads and corrosive conditions, supporting efficient production and maintenance.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with a Class 3A thread fit for superior precision. Key dimensional tolerances include a shoulder diameter of 3/8" (-0.004" to -0.002") and shoulder length of 1/2" (-0.005" to 0.005"). It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free of hazardous substances for safe use in regulated industries.