S-90200A591 5/16"-18 x 2 1/4" Thumb Screws

Key Features & Benefits at a Glance

• Easy manual installation and removal with a knurled thumb head that provides superior grip without tools
• Enhanced corrosion resistance thanks to the black-oxide steel finish, ideal for various industrial environments
• Reliable holding power with 70,000 psi tensile strength and Rockwell B84 hardness for demanding applications
• Quick assembly in coarse materials using 5/16"-18 UNC coarse threading and Class 2A fit for consistent performance
• Space-saving low-profile design with a round head that fits tight clearances while maintaining easy access
• Full-thread engagement along the 2 1/4" length for secure fastening across the entire shank
• Compliance with environmental standards including RoHS 3 and REACH, ensuring safe and sustainable use

Professional Applications & Engineering Value

This black-oxide steel thumb screw is engineered to address common challenges in industrial settings, such as the need for frequent adjustments and tool-free operation. The knurled low-profile head allows operators to tighten or loosen the screw quickly by hand, reducing downtime in maintenance panels, machinery guards, and electronic enclosures. Made from robust steel with a black-oxide finish, it resists rust and wear in humid or corrosive environments. The 5/16"-18 UNC coarse thread and Class 2A fit ensure easy starts and reliable engagement in softer materials or pre-tapped holes, while the fully threaded design provides consistent clamping force. Ideal for applications requiring manual fasteners with high strength and durability, this screw simplifies assembly processes and enhances operational efficiency.

Specification Summary & Compliance

This thumb screw adheres to UNC thread standards with a Class 2A thread fit for precise dimensional accuracy and smooth engagement. It is manufactured to meet RoHS 3 (2015/863/EU) compliance with exemption 6(a)-I and is REACH (EC 1907/2006) compliant, ensuring it meets strict environmental and safety regulations. The specifications include a thread size of 5/16"-18, coarse thread spacing, right-hand thread direction, and full threading along the 2 1/4" length, providing reliable performance in industrial fastening applications.