S-8077A672 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 or chemical-exposed environments.
• Enhanced durability and wear resistance provided by the black oxide finish, which also reduces light reflection.
• Secure, non-slip installation thanks to the knurled socket head and 3/16" hex drive, preventing tool slippage.
• High load-bearing capacity with 70,000 psi tensile strength and 35,000 psi shear strength for demanding applications.
• Precise alignment and smooth rotation ensured by the Class 3A fine thread fit and standard shoulder fit.
• Reliable performance in regulated industries with full compliance to ASME B18.3, RoHS 3, and REACH standards.
• Excellent mechanical stability from Rockwell B79 hardness, maintaining integrity under stress.

Professional Applications & Engineering Value

This 1/4"-28 UNF shoulder screw is engineered to address critical challenges in precision assembly and motion control systems. The 316 stainless steel material offers exceptional resistance to corrosion and oxidation, making it suitable for marine, chemical processing, and food-grade equipment where moisture and chemicals are prevalent. The black oxide finish not only enhances aesthetic appeal but also provides an additional layer of protection against wear and galling. With its fine thread and Class 3A thread fit, this screw ensures tight tolerances and vibration resistance in high-speed machinery, robotics, and automotive linkages. The knurled socket head and hex drive design facilitate quick, secure installation with standard tools, reducing assembly time and improving workplace safety. Ideal for pivots, guides, and spacers, this component delivers long-term reliability and reduces maintenance frequency in industrial settings.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit for high precision and features a UNF fine thread (1/4"-28) with a thread length of 3/8". The shoulder diameter is 3/8" with a tolerance of -0.004" to -0.002", and the shoulder length is 1 1/4" with a tolerance of -0.005" to 0.005". Manufactured in compliance with ASME B18.3 standards, it also meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safety and sustainability in industrial applications.