Electro Hardware P561M10F21-440 Female Standoff 4-40

Product Description

The ELECTRO HARDWARE P561M10F21-440 is a round female standoff designed to create a fixed, threaded space between two panels or PCBs. The standoff is fully threaded internally with a 4-40 thread and measures 1 inch in overall length with a 1/4 inch outside diameter. Constructed from Grade 2 steel and finished with a zinc plating that meets ASTM B633 Type 1 and QQ-S-633 standards, it delivers corrosion resistance suited to general industrial and electronic assembly environments. Electricians, panel builders, and electronics technicians install this type of hardware during equipment fabrication, enclosure assembly, and circuit board mounting applications.

This standoff fits residential and commercial applications wherever a secure, threaded female mount point is required between mating components. Typical use cases include control panel builds, electronic enclosures, DIN rail assemblies, and PCB stacking configurations. The fully threaded internal bore runs the full 1 inch body length, maximizing thread engagement for the mating fastener. The inch measurement system and 4-40 thread size make it compatible with standard North American hardware and fastener tooling.

Key Features

• Fully threaded internal bore for maximum thread engagement along the entire 1 inch body length
• 4-40 thread size suits standard North American electronic and panel hardware
• Grade 2 steel construction provides solid mechanical strength for general-purpose fastening
• Zinc-plated finish meets ASTM B633 Type 1 and QQ-S-633 corrosion resistance standards
• Round body profile with 1/4 inch OD fits standard clearance holes and mounting cutouts
• Length tolerance held to plus or minus 0.005 inches for consistent stack height in precision assemblies

Compatibility

Designed as a standard inch-series female standoff for use with 4-40 threaded fasteners in electronic enclosures, control panels, and PCB mounting applications where a 1 inch standoff height is required.

Installation Notes

Installation is performed by hand or with a hex driver or pliers sized to the 1/4 inch OD round body. Ensure the mating panel hole is sized correctly to allow flush seating of the standoff before threading the mating screws. Do not overtighten mating fasteners into the female thread, as Grade 2 steel threads can be damaged by excessive torque from power tools. Follow applicable enclosure and panel wiring codes, such as NEC requirements, when using standoffs inside electrical enclosures.