S-91833A148 4-40 Thumb Nuts

Key Features & Benefits at a Glance

• Effortless manual adjustments with a knurled round head for superior grip in tight spaces
• Long-lasting corrosion resistance thanks to durable 18-8 Stainless Steel construction
• Secure and reliable fastening ensured by UNC coarse threading with Class 2B fit
• Versatile partial threading design allows for precise positioning and easy assembly
• Optimized collar dimensions (1/4" diameter, 1/2" height) for stable mounting and load distribution
• Compliance with strict environmental standards including RoHS 3 and REACH for safe industrial use
• Right-hand thread direction provides intuitive installation for standard applications

Professional Applications & Engineering Value

This 4-40 UNC thumb nut is engineered to address common industrial challenges like frequent manual adjustments and exposure to corrosive environments. The 18-8 Stainless Steel material offers excellent resistance to rust and oxidation, making it ideal for machinery, electronic enclosures, and outdoor equipment where durability is critical. The knurled round head ensures a firm grip even with oily hands or gloves, reducing slippage and enhancing operator safety. With its partially threaded design and coarse UNC thread, it provides quick installation and reliable holding power in vibration-prone applications, minimizing maintenance downtime and improving assembly efficiency.

Specification Summary & Compliance

This thumb nut features precision 4-40 UNC coarse threads with a Class 2B fit for consistent engagement and dimensional accuracy. The threading is partially threaded (3/8" depth) with a right-hand direction. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and suitable for use in regulated industries. Manufactured to standard inch system specifications, it guarantees reliable performance in various mechanical and industrial assemblies.