4-40 x 1/2 Brass Button Head Socket Cap Screw is used where reduced head projection and a clean visible appearance are important on brass hardware. The internal hex drive keeps the installation tool inside the head, which is useful when external wrench clearance is limited. Brass is appropriate for many low-load mechanical assemblies where corrosion resistance in general service, appearance, and electrical behavior matter.

Appropriate uses include electronic equipment and display hardware, where a decorative appearance and lower head projection help exposed hardware look intentional. It can also fit electrical assemblies and control panels, where conductivity and non-magnetic construction can be useful around selected hardware and instrumentation layouts. The internal hex drive supports socket-key installation in compact equipment without relying on an external wrenching surface.

For the 4-40 thread and 1/2 in. length, the reference head diameter is 0.201-0.213 in. and the head height is 0.051-0.059 in. Use the verified dimensions below when checking head projection, socket access, and replacement fit.

Technical Highlights

• Material: Brass
• Thread Size: 4-40
• Length: 1/2 in.
• Nominal Body Diameter: #4 (.112 in.)
• Head Diameter: 0.201-0.213 in.
• Head Height: 0.051-0.059 in.
• Hex-Key Size: 1/16 in.
• Drive Type: Internal Hex

Reference dimensions may vary slightly by manufacturer.