S-90181A537 1/4"-20 x 1/2" Thumb Screws

Key Features & Benefits at a Glance

• Effortless hand-tightening with a wide spade head design, eliminating the need for tools in quick assembly or adjustment scenarios
• Superior durability and load-bearing capacity from high-strength steel construction, supporting up to 40,000 psi tensile strength for reliable performance
• Enhanced wear resistance due to Rockwell B55 hardness, ensuring long service life even with frequent manual use
• Quick and secure coarse threading with UNC 1/4"-20 specification, enabling faster installation and reduced cross-threading risk
• Precise thread engagement guaranteed by Class 2A fit, providing consistent clamping force and vibration resistance in dynamic environments
• Full-length threading for maximum grip along the entire 1/2" length, offering versatile positioning and holding power
• Right-hand thread direction for intuitive, standard clockwise tightening, simplifying operator training and reducing installation errors

Professional Applications & Engineering Value

This steel thumb screw is engineered to address common industrial challenges where tool-free, rapid access and secure fastening are critical. The spade head provides ample surface area for comfortable hand-tightening, making it ideal for frequently adjusted components in machinery guards, access panels, and electronic enclosures. Its coarse UNC thread and Class 2A fit ensure quick alignment and robust holding in materials like aluminum or plastic, reducing assembly time while maintaining vibration resistance. The combination of Rockwell B55 hardness and 40,000 psi tensile strength offers reliable performance in demanding environments, from manufacturing equipment to prototyping setups, where durability and repeated manual operation are paramount.

Specification Summary & Compliance

This thumb screw adheres to UNC 1/4"-20 coarse thread standards with Class 2A thread fit for consistent dimensional accuracy and interchangeability. It is fully threaded, with a length of 1/2", and manufactured from high-grade steel. The product meets general industry specifications for mechanical fasteners and is suitable for applications requiring compliance with common engineering standards, though specific certifications like RoHS or REACH should be confirmed based on material sourcing.