Electro Hardware P513M12F21-440 Hex Standoff 4-40

Product Description

The ELECTRO HARDWARE P513M12F21-440 is a female hex circuit board standoff designed to create fixed spacing between printed circuit boards and mounting surfaces. Threaded 4-40 internally, this standoff accepts a mating machine screw to secure stacked PCB assemblies or mount a single board at a set height. The hex body measures 0.25 inches across flats and 0.25 inches in overall length, making it suitable for compact, low-profile board mounting applications. Manufactured from Grade 2 steel with a zinc-plated clear chromate finish per ASTM B633 Type 1 and QQ-S-633, it provides corrosion resistance appropriate for indoor electronic enclosures. Electronics assembly technicians, panel builders, and electricians working on control board installations are the typical end users.

This standoff is used in residential and commercial electronic assemblies where PCBs must be mounted at a defined standoff height above a chassis or secondary board. Typical applications include HVAC control panels, electrical enclosures, and OEM electronic equipment. The 4-40 thread size is one of the most common in light-duty PCB hardware, making this part a standard choice wherever fine-thread inch-series standoffs are called for in board stack-up assemblies.

Key Features

• Female 4-40 internal thread accepts standard 4-40 machine screws for secure board mounting
• Hex body shape at 0.25 inches across flats allows tightening with standard hex drivers or nut drivers
• 0.25 inches overall length provides low-profile standoff height for compact PCB assemblies
• Grade 2 steel construction with zinc-plated clear chromate finish meets ASTM B633 Type 1 and QQ-S-633 standards
• Length tolerance of -0.005 to +0.005 inches ensures consistent stack height across multi-board assemblies

Compatibility

Designed as a standard inch-series female hex standoff for PCB mounting applications using 4-40 thread fasteners in electronic enclosures and control panel assemblies.

Installation Notes

Installation is typically performed by electronics assembly technicians or electricians during control panel build or board replacement. Power down and de-energize any enclosure before installing or removing standoffs from live assemblies. Use a correctly sized hex driver or nut driver matching the 0.25-inch across-flats dimension to avoid rounding the hex body. Do not overtighten mating screws, as the fine 4-40 thread in steel can be damaged by excessive torque applied with power tools.