S-91205A542 1/4"-20 x 1" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Superior vibration resistance with integrated Nylon Patch thread locker, preventing loosening under dynamic loads and reducing maintenance needs.
• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, minimizing the risk of fastener failure.
• High hardness (Rockwell C37) provides excellent wear resistance and durability, extending the screw's service life in demanding environments.
• Precise Class 3A thread fit offers tighter tolerances for smoother assembly and more secure, reliable fastening connections.
• Wide operating temperature range (-70° to 250° F) allows consistent performance in both extreme cold and high-heat industrial settings.
• Corrosion-resistant Black-Oxide finish on alloy steel enhances protection against rust and wear, ideal for harsh conditions.
• Standard hex drive design enables easy installation and removal with common tools, improving assembly efficiency.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in industrial assembly, such as vibration-induced loosening and mechanical stress. The Nylon Patch thread locker embedded in the UNC coarse threads provides a permanent locking mechanism that maintains clamp load without requiring additional adhesives, making it ideal for machinery, automotive, and aerospace applications where reliability is paramount. Its high tensile strength and robust Rockwell C37 hardness ensure it withstands heavy loads and repetitive use, reducing downtime and replacement costs. The right-hand thread direction and fully threaded design facilitate quick, secure fastening in tight spaces, enhancing productivity in automated or manual assembly lines.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with a Class 3A thread fit for high precision and consistent performance. It is manufactured in compliance with ASME B18.3 specifications and meets ASTM A574 material standards. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring adherence to environmental and safety regulations for industrial use.