S-94622A211 1/4"-28 x 17/32" AN4-4 Cotter Pin-Lockable Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure.
• Cadmium-plated steel construction provides superior corrosion resistance, extending service life in harsh industrial or aerospace environments.
• Class 3A thread fit offers precise, tight tolerances for secure fastening and vibration resistance in critical assemblies.
• Cotter pin locking mechanism with a 1/16" pin diameter prevents loosening from dynamic loads, enhancing safety in moving parts.
• External hex drive design allows for easy installation and removal with standard tools, improving maintenance efficiency.
• Fine UNF threading (28 threads per inch) delivers better load distribution and sealing capabilities compared to coarse threads.
• AN4-4 specification compliance guarantees adherence to aerospace standards, ensuring reliability for regulated applications.

Professional Applications & Engineering Value

This 1/4"-28 UNF hex head screw is engineered to address common challenges in aerospace and heavy industrial settings, where vibration, high loads, and environmental factors can compromise fastener integrity. The cadmium-plated steel material combats corrosion, while the Rockwell C26 hardness ensures durability against wear. The partially threaded design with a precise grip length allows for controlled clamping force, minimizing stress concentration. The integrated cotter pin locking feature secures the screw in place, preventing accidental disassembly in dynamic systems like control linkages or machinery. By meeting AN4-4 specifications, it provides a trusted solution for applications demanding strict compliance and repeatable performance, reducing downtime and maintenance costs.

Specification Summary & Compliance

This screw features a Class 3A thread fit for high precision, with UNF fine threads (1/4"-28) and a right-hand thread direction. Dimensions include a thread length of 15/32", overall length of 17/32", and hole diameter of 0.076" for cotter pin compatibility. It is manufactured in the inch system and conforms to AN4-4 specifications, ensuring adherence to established aerospace and industrial standards for reliable, consistent performance.