S-90179A593 5/16"-18 x 2 1/2" Thumb Screws

Key Features & Benefits at a Glance

• Enhanced manual torque application with comfortable spade head design (3/4" height, 11/16" width) for easy hand-tightening without tools
• Superior load distribution and vibration resistance thanks to the integrated flange (0.563" diameter) that increases surface contact area
• High-strength steel construction with Rockwell B55 hardness and 40,000 psi tensile strength for reliable performance in demanding environments
• Quick and secure coarse threading with 5/16"-18 UNC Class 2A fit ensures fast installation and consistent holding power
• Full-length threading provides maximum engagement depth and versatile positioning along the entire 2 1/2" length
• Right-hand thread direction offers standard, intuitive tightening for common industrial applications
• Durable, long-lasting fastening solution resistant to wear and deformation under repeated use

Professional Applications & Engineering Value

This heavy-duty thumb screw addresses critical needs in industrial assembly and maintenance where tool-free, high-torque fastening is essential. The steel construction with Rockwell B55 hardness ensures it withstands mechanical stress and resists deformation, while the 40,000 psi tensile strength provides reliable clamping force for secure joints. The spade head and flange work together to distribute pressure evenly, preventing surface damage and reducing loosening from vibrations—common issues in machinery, electronic enclosures, and fixture applications. With fully threaded UNC coarse threads and Class 2A fit, it enables rapid installation and removal, making it ideal for adjustable components, access panels, and repetitive-use assemblies where efficiency and durability are paramount.

Specification Summary & Compliance

This thumb screw adheres to UNC thread standards with a 5/16"-18 coarse thread and Class 2A thread fit for consistent dimensional accuracy. It is fully threaded and features a right-hand thread direction. Manufactured from high-grade steel, it meets general industry specifications for mechanical fasteners. The product is designed to conform with common industrial requirements, though specific compliance such as RoHS or REACH should be verified per batch if applicable.