Electro Hardware THS3052M01F21 Brass Thumb Screw 1/4-20

Product Description

The ELECTRO HARDWARE THS3052M01F21 is a brass thumb screw designed for hand-tightened fastening applications where tools are not required. It features a knurled head for improved grip and a 1/4-20 UNC thread with a 1/2-inch thread length. The head measures 1/2 inch in diameter and 1/4 inch in height, giving it a low-profile form suitable for panel assemblies, fixtures, and enclosures. The screw has a zinc finish applied over a brass body, providing moderate corrosion resistance for light-duty service environments. Overall length is 3/4 inch. This part is sold individually and is handled by maintenance technicians, electricians, and mechanical assemblers.

This thumb screw is suited for use in control panels, electrical enclosures, instrument housings, and light mechanical assemblies where frequent hand removal is required. The knurled head allows repeated fastening and loosening without tooling, making it a practical choice in service access points and equipment covers. It is commonly used in commercial and light industrial settings where 1/4-20 UNC threaded inserts or clearance holes are present in sheet metal, plastic, or machined components.

Key Features

• 1/4-20 UNC thread standard for broad fastener compatibility
• Knurled head design allows tool-free hand tightening and loosening
• Brass head and body construction with zinc finish for corrosion resistance
• 1/2-inch head diameter and 1/4-inch head height for low-profile clearance
• 3/4-inch overall length with 1/2-inch thread engagement length
• Meets ASTM B633, QQ-B-626B Comp 22, and Type 1 standards

Compatibility

Designed as a hand-drive replacement or new-installation thumb screw for applications with 1/4-20 UNC threaded inserts or tapped holes in panels, enclosures, and light mechanical assemblies.

Installation Notes

Install by hand into a 1/4-20 UNC tapped hole or threaded insert. De-energize any electrical enclosure before accessing internal fasteners. Do not use power tools on this screw, as knurled-head thumb screws are not rated for torque-tool installation and may damage the head or mating thread. Verify thread engagement of at least 1/2 inch for adequate holding strength in the application.