S-8077A864 1/4"-28 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel 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, heavy-duty applications
• Precise Class 3A thread fit ensures tight tolerances and secure fastening in high-vibration settings
• Enhanced grip and torque application from the knurled socket head with 5/32" hex drive, reducing slippage
• Accurate alignment and spacing with a 5/16" shoulder diameter and 1/4" shoulder length for consistent component positioning
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and regulatory adherence
• Fine UNF threading (1/4"-28) provides superior holding power and resistance to loosening in precision assemblies

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw with a black oxide finish is engineered to address critical challenges in precision machinery, automation systems, and corrosive environments. Its Class 3A thread fit and fine 1/4"-28 UNF threads deliver reliable performance in applications requiring minimal backlash and high repeatability, such as robotic arms, conveyor systems, and optical equipment. The knurled socket head and hex drive enable efficient installation with standard tools, reducing assembly time and preventing damage. With a Rockwell B79 hardness and robust shoulder design, it maintains alignment under dynamic loads, making it ideal for pivots, bearings, and guides where dimensional stability is crucial. This screw’s corrosion-resistant properties and compliance with ASME B18.3 standards ensure long-term durability and reduced maintenance in demanding industrial settings.

Specification Summary & Compliance

This shoulder screw features precise dimensions, including a Class 3A thread fit for tight tolerances, 1/4"-28 UNF fine threads, and shoulder diameter/length tolerances (e.g., -0.004" to -0.002" for diameter). It adheres to ASME B18.3 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity for global industrial use.