S-95150A148 4-40 Thumb Nuts

Key Features & Benefits at a Glance

• Superior corrosion resistance with Black-Oxide 18-8 Stainless Steel construction, ideal for harsh environments and extending service life.
• Effortless hand-tightening and secure grip thanks to the knurled round head and flanged design, eliminating the need for tools in quick assembly.
• Reliable and precise thread engagement with a 4-40 UNC coarse thread and Class 2B fit, ensuring consistent performance and reducing cross-threading risks.
• Enhanced stability and load distribution from the integrated flange, which acts as a built-in washer to prevent loosening under vibration.
• Durable and long-lasting performance due to the robust 18-8 stainless steel material, capable of withstanding repeated use without degradation.
• Compliance with major environmental and safety standards, including RoHS 3 and REACH, making it suitable for regulated industries and global supply chains.
• Versatile right-hand threading for standard applications, providing broad compatibility with common UNC fasteners.

Professional Applications & Engineering Value

This 4-40 UNC Thumb Nut is engineered to solve common industrial challenges where tool-free, rapid fastening is essential. The Black-Oxide 18-8 Stainless Steel offers excellent corrosion resistance, making it ideal for outdoor equipment, electronic enclosures, and machinery in humid or corrosive settings. The flanged design increases the bearing surface, reducing surface pressure and minimizing the risk of material damage, while the knurled head ensures a firm grip even with gloved hands. Its coarse UNC threading and Class 2B fit provide quick installation and reliable holding power, which is critical in assembly lines, maintenance panels, and adjustable components where vibration resistance and ease of use are priorities. This nut delivers consistent performance in applications demanding both durability and user convenience.

Specification Summary & Compliance

This thumb nut adheres to UNC thread standards with a 4-40 thread size and Class 2B thread fit for precise dimensional accuracy. It features a collar diameter of 1/4", head diameter of 5/16", and fully threaded right-hand coarse spacing. The product is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and suitable for various industrial and consumer applications.