S-8077A667 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 environments including marine and chemical processing applications.
• Enhanced wear resistance and reduced light reflection from the black oxide finish, providing long-lasting performance and a professional appearance.
• High-strength, precision alignment with a 2" shoulder and Class 3A thread fit, ensuring accurate component positioning and reduced assembly vibration.
• Exceptional mechanical durability with a tensile strength of 70,000 psi and Rockwell B79 hardness, capable of withstanding high-stress industrial loads.
• Secure, non-slip fastening thanks to the knurled socket head and hex drive, allowing for high-torque installation without tool slippage.
• Reliable fine-thread engagement with the 1/4"-28 UNF thread, providing superior resistance to loosening under dynamic loads compared to coarse threads.
• Full regulatory compliance with ASME B18.3, RoHS 3, and REACH standards, ensuring safety and environmental responsibility for global supply chains.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to solve critical alignment and durability challenges in precision machinery and industrial assembly. The 2" shoulder length provides a stable pivot or bearing surface, eliminating the need for separate spacers and reducing component count. The black oxide finish on the corrosion-resistant 316 material significantly extends service life in humid or chemically aggressive environments, preventing seizure and thread galling. Combined with the Class 3A UNF fine thread and hex socket drive, it ensures vibration-resistant fastening and easy installation in confined spaces, making it an ideal precision shoulder screw for robotics, conveyor systems, and automated equipment where reliability is non-negotiable.

Specification Summary & Compliance

This shoulder screw maintains high dimensional accuracy with a Class 3A thread fit and shoulder tolerances (Diameter: -0.004" to -0.002"; Length: -0.005" to 0.005"). It is manufactured to the UNF fine thread standard (1/4"-28) and conforms to the ASME B18.3 specification for socket head shoulder screws. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances for safe use in industrial and consumer applications.