Electro Hardware P421M09F16440 Hex Standoff 4-40 2-1/4in

Product Description

The ELECTRO HARDWARE P421M09F16440 is a female hex circuit board standoff designed to create fixed spacing between a PCB and a mounting surface or between stacked boards. Threaded 4-40 on the female end with a 1/4 inch thread depth, it accepts a mating screw to secure the board firmly in place. The hex body measures 3/16 inches across flats, allowing a standard hex driver or wrench to install and torque it without slipping. Machined from 303 stainless steel with a plain bright finish, this standoff meets QQ-S-763 fastener standards and resists corrosion in demanding environments. Electronics assemblers, panel builders, and HVAC control board technicians are the typical installers.

This standoff is used wherever a circuit board must be mounted at a fixed height above a chassis or enclosure floor, including residential and commercial HVAC control panels, industrial equipment enclosures, and electronic assembly applications. The 2-1/4 inch overall length provides ample clearance for components mounted on the underside of the board or for routing wire harnesses between the board and the panel surface. The inch measurement system and 4-40 thread size make it a standard fit for North American PCB assembly work.

Key Features

• Female 4-40 thread with 1/4 inch thread depth for secure board fastening
• 2-1/4 inch overall length provides generous standoff clearance
• Hex body at 3/16 inches across flats for wrench-assisted installation
• 303 stainless steel construction meets QQ-S-763 fastener standard
• Plain bright finish with no coating that could affect dimensional tolerances
• Length tolerance held to plus or minus 0.005 inches for precise stacking

Compatibility

Designed as an OEM-style replacement or new-installation standoff for circuit boards using 4-40 screw fastening systems in inch-measurement assemblies.

Installation Notes

Installation is performed by electronics technicians or HVAC controls specialists. De-energize all equipment and discharge any capacitors before handling circuit boards. Use a hex driver or open-end wrench sized for 3/16 inch across flats to seat the standoff firmly without overtightening, which can crack PCB laminate. Follow the equipment manufacturer's assembly documentation for board mounting sequence and screw engagement depth.