S-90807A118 1/4"-20 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Load-Bearing Capacity – With 140,000 psi tensile strength and Rockwell C32 hardness, this screw withstands high-stress applications without deformation.
• Precision Thread Fit – Class 3A thread ensures tight, secure fastening with minimal backlash in assemblies requiring exact alignment.
• Corrosion-Resistant Finish – Black oxide coating enhances durability and provides moderate protection against rust in industrial environments.
• Secure Grip & Easy Installation – Knurled socket head and 1/8" hex drive allow for firm tool engagement and straightforward torque application.
• Stable Shoulder Alignment – 1-1/2" shoulder length with controlled tolerances maintains precise component positioning and rotational stability.
• Wide Compatibility – UNC coarse 1/4"-20 thread design facilitates quick assembly and is compatible with standard industrial components.
• Environmental & Regulatory Compliance – Meets RoHS 3 and REACH standards, ensuring safe use in regulated markets and eco-conscious operations.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical alignment and wear challenges in precision machinery, such as rotating shafts, gears, and linkages. The black oxide finish not only resists corrosion but also reduces galling during repeated adjustments. With a Class 3A thread fit and UNC coarse thread, it ensures rapid assembly while maintaining positional accuracy under vibration. The 1-1/2" shoulder length provides a stable bearing surface, minimizing eccentric movement in industrial automation and assembly jigs. Its high tensile strength and knurled socket head make it ideal for applications demanding both durability and easy maintenance.

Specification Summary & Compliance

This shoulder screw adheres to UNC thread standards with a Class 3A fit for precise engagement. Shoulder diameter tolerance is -0.004" to -0.002", and shoulder length tolerance is -0.005" to 0.005" to ensure consistent performance. Manufactured from alloy steel and finished with black oxide, it complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting use in environmentally sensitive and high-reliability sectors.