Electro Hardware P529M03F21-440 Female Hex Standoff 4-40

Product Description

The ELECTRO HARDWARE P529M03F21-440 is a female hex circuit board standoff designed to mount and space printed circuit boards within enclosures and electronic assemblies. The standoff features a 4-40 female threaded bore, a 0.5 inch overall length, and a 0.25 inch width across the hex flats. Manufactured from brass with a zinc-plated finish certified to ASTM B633 Type 1 and QQ-B-626 Comp 22, this standoff provides corrosion resistance and reliable electrical isolation between stacked boards. It is installed by electronics technicians, field service engineers, and industrial maintenance professionals working on control panels and PCB assemblies.

This standoff is suited for residential and commercial control board assemblies, industrial automation enclosures, and any application requiring precise PCB-to-surface or PCB-to-PCB spacing using 4-40 threaded hardware. The hex body shape allows installation and removal with standard hex drivers or nut drivers, making it practical in tight-tolerance layouts where boards must be securely mounted without direct contact with chassis surfaces. The zinc-plated brass construction is appropriate for indoor and protected environments.

Key Features

• 4-40 female threaded bore for standard inch-series 4-40 fasteners
• 0.5 inch overall length with a tight length tolerance of -0.005 to +0.005 inches
• Hex body profile, 0.25 inch width across flats, compatible with standard nut drivers
• Brass base material with zinc-plated finish meeting ASTM B633 Type 1 and QQ-B-626 Comp 22
• Inch measurement system - fits standard imperial PCB mounting layouts

Compatibility

Designed as an OEM-style replacement or new-installation standoff for circuit board assemblies using 4-40 inch-series threaded fasteners in industrial, commercial, and residential control panel applications.

Installation Notes

Installation is performed by electronics technicians or qualified control panel assemblers. Power down and de-energize all circuits before handling PCBs or standoffs in live enclosures. Use a correctly sized nut driver or hex driver matching the 0.25 inch across-flats dimension to avoid rounding the hex body. Do not over-torque - brass standoffs are susceptible to thread damage if excessive force is applied.