Electro Hardware P577M01F21-440 Female Standoff 4-40

Product Description

The ELECTRO HARDWARE P577M01F21-440 is a round female standoff designed for use in panel assemblies, electronic enclosures, and precision fastening applications. It features a 4-40 thread size with a 1 inch thread depth, a 1-1/4 inch overall length, and a 1/4 inch outside diameter. Constructed from brass with a zinc-plated finish meeting ASTM B633 Type 1 and QQ-B-626 Comp 22 standards, this standoff is fully threaded and built for reliable engagement in tight-tolerance installations. Electricians, panel builders, and electronics assembly technicians commonly use standoffs of this type when mounting PCBs, panels, or sub-assemblies with controlled spacing.

This standoff is suited for light-duty electronic and electrical panel assembly work where precise spacing between components or surfaces is required. The fully threaded female interior accepts a mating male fastener from either end, making it useful in stacked-board configurations and chassis assemblies. The compact 1/4 inch OD allows installation in confined layouts. Its brass construction provides good conductivity and corrosion resistance, while the zinc plating adds an additional layer of surface protection for indoor industrial and commercial environments.

Key Features

• 4-40 thread size with 1 inch full thread depth for secure fastener engagement
• 1-1/4 inch overall length with tight length tolerance of -0.005 to 0.005 inches
• 1/4 inch outside diameter round body for use in space-constrained assemblies
• Brass construction with zinc-plated finish per ASTM B633 Type 1 and QQ-B-626 Comp 22
• Fully threaded interior allows mating fasteners from either end

Compatibility

Designed as a standard inch-series female standoff for use in electronic panel assemblies, PCB mounting applications, and chassis builds that require 4-40 threaded hardware.

Installation Notes

Installation is typically performed by panel builders or electronics assembly technicians using a hex driver or wrench sized to the 1/4 inch OD body. Power down all circuits before working inside enclosures or panels. Avoid over-torquing brass standoffs, as the material is softer than steel and susceptible to thread damage under excessive force. Confirm thread engagement depth and mating fastener length before final assembly.