Electro Hardware P309M12F21440 Hex Standoff 4-40 1/2 Inch

Product Description

The ELECTRO HARDWARE P309M12F21440 is a female hex circuit board standoff designed to create precise spacing between PCBs and mounting surfaces in electronic assemblies. Machined from steel with a clear zinc chromate finish meeting ASTM B633 Type 1 and QQ-S-633 standards, this standoff accepts a 4-40 threaded fastener and provides a 0.5-inch overall length with a fully threaded interior through the entire 0.5-inch thread depth. The hexagonal body measures 3/16 inches across flats, allowing standard hex-driver installation. Length tolerance is held to plus or minus 0.005 inches, ensuring consistent stack height in multi-board assemblies.

This standoff is used in control board mounting applications across HVAC, electrical, and light industrial equipment. It is suited for residential and commercial equipment builds, panel assembly, and field service repairs where OEM-style board spacing hardware must be replicated. Technicians installing or replacing control boards in furnaces, air handlers, and electrical enclosures commonly use this hardware type to maintain proper clearance and mechanical support between circuit boards and chassis surfaces.

Key Features

• Female 4-40 threaded interior, fully threaded through 0.5-inch thread depth
• Hexagonal body profile, 3/16 inches width across flats, for wrench or hex-driver installation
• 0.5-inch overall length with tight length tolerance of plus or minus 0.005 inches
• Steel construction with clear zinc chromate finish for corrosion resistance
• Meets ASTM B633 Type 1 and QQ-S-633 finish standards
• Material Grade 2 steel for consistent mechanical performance in fastener assemblies

Compatibility

Designed as an OEM-style replacement or service standoff for circuit board mounting applications requiring a 4-40 female hex standoff with a 0.5-inch overall length.

Installation Notes

Installation is typically performed by electronics technicians, HVAC controls specialists, or electricians during control board replacement or panel assembly. Power down and de-energize all circuits before removing or installing circuit board hardware. Use a properly sized hex driver or wrench matched to the 3/16-inch across-flats dimension to avoid rounding the hex body. Do not overtighten mating screws beyond the thread engagement capacity of the standoff.