S-90117A565 1/4"-20 x 2 1/2" ASME B18.3 Alloy Steel Wire-Lockable Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life and maintaining integrity in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening in machinery and equipment.
• Partially threaded design allows for controlled clamping force and easier alignment, ideal for components requiring specific grip range and stability.
• High hardness (Rockwell C37) enhances wear resistance and durability, ensuring long-term performance with minimal deformation under load.
• Hex socket drive (3/16") enables high-torque installation with standard tools, facilitating quick and secure fastening in confined spaces.
• Coarse UNC threading (1/4"-20) offers faster installation and reduced cross-threading risks, improving efficiency in assembly line operations.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in industrial settings, such as vibration-induced loosening and environmental degradation. The combination of high tensile strength (170,000 psi) and Class 3A thread fit ensures a secure, reliable hold in heavy machinery, automotive assemblies, and precision equipment, where failure can lead to costly downtime. The partially threaded configuration allows for optimal load distribution, reducing stress concentrations and enhancing joint integrity. With its coarse UNC thread and hex drive, it streamlines installation in high-volume production environments, while the black-oxide surface resists rust and wear, making it suitable for outdoor or corrosive applications. This screw delivers consistent performance in industrial socket head fastening, supporting long-term operational safety and efficiency.

Specification Summary & Compliance

This product features a 1/4"-20 UNC coarse thread with Class 3A thread fit for precise dimensional accuracy, ensuring reliable engagement and minimal play. It meets ASME B18.3 specifications for socket head cap screws, guaranteeing consistent manufacturing quality. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmental safety and regulatory adherence in global supply chains.