S-8077A798 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 long-lasting performance and reduced maintenance
• Precise alignment and secure fit thanks to the Class 3A thread fit and standard shoulder, minimizing assembly errors and vibration loosening
• High tensile and shear strength (70,000 psi tensile, 35,000 psi shear) for reliable load-bearing in demanding applications
• Easy installation and removal with the hex socket drive and knurled head, allowing for efficient tool engagement and reduced slippage
• Consistent dimensional accuracy ensured by ASME B18.3 compliance, guaranteeing interchangeability and fit in standardized assemblies
• Environmental and safety compliance with RoHS 3 and REACH standards, making it suitable for regulated industries and global supply chains

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw with a black oxide finish is engineered to address common industrial challenges such as corrosion, misalignment, and mechanical failure. The UNC coarse threading and Class 3A fit provide excellent engagement in soft materials or high-vibration settings, reducing the risk of stripping and ensuring reliable fastening. The precise shoulder diameter and length offer stable pivoting and spacing in machinery, robotics, and automotive assemblies, while the knurled head enhances grip during manual adjustments. Ideal for precision shoulder bolts in conveyor systems, pivoting joints, and electronic enclosures, it combines high tensile strength with corrosion resistance to extend service life and minimize downtime in demanding environments.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC thread with Class 3A fit for tight tolerances and secure fastening. The shoulder diameter is 5/16" with a tolerance of -0.004" to -0.002", and the shoulder length is 7/32" with a tolerance of -0.005" to 0.005", ensuring precise alignment. It meets ASME B18.3 specifications for dimensional consistency and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, supporting safe and environmentally responsible use in industrial applications.