S-91746A114 4-40 x 3/8" Thumb Screws

Key Features & Benefits at a Glance

• Enhanced Grip & Effortless Adjustment: Knurled head texture provides superior finger traction for quick, tool-free operation in tight spaces.
• Exceptional Corrosion Resistance: Made from 18-8 Stainless Steel, offering reliable performance in demanding environments and resisting rust.
• High Tensile Strength for Demanding Applications: With a 80,000 psi tensile strength and Rockwell B85 hardness, this screw withstands significant mechanical stress and repeated use.
• Optimized Low-Profile Design: The round, low-profile head minimizes protrusion, making it ideal for applications with limited clearance.
• Precision Thread Fit for Secure Fastening: Class 2A thread fit on the 4-40 UNC coarse thread ensures consistent, reliable engagement and vibration resistance.
• Full Thread Engagement: The fully threaded design allows for maximum adjustability and holding power along the entire 3/8" length.
• Compliant with Global Standards: Meets RoHS 3 and REACH regulations, ensuring environmental safety and suitability for international markets.

Professional Applications & Engineering Value

This 4-40 UNC thumb screw is engineered to solve common assembly challenges where tool access is limited and frequent adjustments are necessary. The low-profile, knurled round head offers exceptional manual control, eliminating the need for tools and speeding up maintenance on panels, access doors, and electronic enclosures. Constructed from 18-8 Stainless Steel, it provides excellent corrosion resistance, making it suitable for use in harsh industrial, marine, or outdoor settings. The coarse UNC thread and Class 2A fit ensure quick installation and a secure hold, reducing the risk of cross-threading and loosening under vibration. This combination of durable materials, user-friendly design, and precision threading delivers reliable performance in applications ranging from securing electronic components to fastening machinery guards.

Specification Summary & Compliance

This thumb screw adheres to the Unified National Coarse (UNC) thread standard with a Class 2A tolerance for consistent, precise fit. Key dimensional specifications include a 4-40 thread size, 0.112" thread diameter, 3/8" length, and a 5/16" head diameter. The manufacturing and material composition are fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety and environmental responsibility for global industrial use.