S-91385A544 1/4"-20 x 1 1/4" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Permanent Vibration Resistance: Integrated Nylon Patch thread locker ensures reliable, long-term fastening without loosening under dynamic loads.
• Superior Material Strength: Made from Black-Oxide Alloy Steel with a Rockwell C45 hardness for excellent wear resistance and durability in demanding applications.
• Wide Temperature Performance: Maintains locking integrity across an extensive range from -50°F to 250°F, suitable for both low and high-temperature environments.
• Precise & Secure Fastening: Features a Class 3A thread fit and UNC coarse thread for easier assembly and a tighter, more secure hold.
• Effective Grip & Alignment: The cup point tip bites securely into the contact surface, providing strong resistance to rotational forces and improving part alignment.
• Easy Installation in Confined Spaces: Headless design with a 1/8" hex drive allows for installation in tight spaces and provides a flush finish.
• Trusted Compliance & Reliability: Manufactured to meet ASME B18.3 specifications and is compliant with RoHS 3 and REACH environmental standards.

Professional Applications & Engineering Value

This 1/4"-20 UNC set screw is engineered to solve critical challenges in industrial assemblies where vibration, thermal cycling, and space constraints are common. The Black-Oxide Alloy Steel construction provides a robust base that resists corrosion and wear, while the permanent Nylon Patch thread locker eliminates the need for secondary locking devices, reducing assembly time and cost. Its cup point design ensures maximum grip on shafts, gears, and pulleys, preventing slippage in high-torque applications. Ideal for use in machinery, automotive components, and precision equipment, this headless screw with a hex drive offers a reliable, maintenance-free solution that upholds assembly integrity under strenuous conditions.

Specification Summary & Compliance

This set screw adheres to a Class 3A thread fit for high precision in UNC coarse threads, ensuring consistent performance. It is manufactured in compliance with the ASME B18.3 standard and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for global markets and environmentally conscious procurement.