Electro Hardware P593M03F21-440 Hex Standoff 4-40

Product Description

The ELECTRO HARDWARE P593M03F21-440 is a female hex circuit board standoff designed to mount and space printed circuit boards within electronic enclosures and control panels. Machined from brass with a zinc-plated clear chromate finish, this standoff measures 1.5 inches overall length with a 0.25-inch width across flats. The internal 4-40 threaded bore accepts a standard 4-40 machine screw on each end, allowing boards to be stacked or secured to a chassis at a fixed, consistent height. The hexagonal body provides a flat surface for wrenching during installation and removal. It meets ASTM B633 Type 1 and QQ-B-626 Comp 22 finish standards.

This standoff is used in residential and commercial electronic control assemblies, HVAC control boards, relay panels, and general electrical enclosures where circuit boards require rigid mechanical support and precise spacing. HVAC technicians, electricians, and electronics assembly professionals install these standoffs when replacing or mounting control boards in equipment requiring a secure, vibration-resistant board mount. The 4-40 thread size is common across a wide range of light-duty PCB mounting applications.

Key Features

• Female 4-40 threaded hex body accepts 4-40 machine screws for secure board stacking or chassis mounting
• 1.5-inch overall length provides consistent board-to-chassis spacing
• Brass construction offers corrosion resistance and reliable electrical conductivity where grounding through the standoff is required
• Zinc-plated clear chromate finish meets ASTM B633 Type 1 and QQ-B-626 Comp 22 standards
• Hexagonal body shape allows wrench engagement for controlled installation torque
• 0.25-inch width across flats fits standard hex drivers and nut drivers

Compatibility

Designed as an OEM-style replacement or new-installation standoff for circuit boards using 4-40 threaded fasteners in residential and commercial electronic control assemblies.

Installation Notes

Installed by electricians, HVAC technicians, or electronics assembly professionals. Always de-energize and lock out the equipment before servicing any control board or mounting hardware. Use a properly sized hex driver or nut driver matching the 0.25-inch width across flats to avoid rounding the hex body. Avoid over-tightening, which can stress the PCB mounting holes or strip the 4-40 threads.