Electro Hardware P577M03F21-440 Hex Standoff 4-40

Product Description

The ELECTRO HARDWARE P577M03F21-440 is a female hex circuit board standoff designed to mount and space printed circuit boards within enclosures and electronic assemblies. Threaded 4-40 on the female end, this standoff measures 1.25 inches overall length with a 0.25-inch width across the hex flats. The body is machined brass with a clear zinc chromate finish applied to ASTM B633 Type 1 and QQ-B-626 Comp 22 standards, providing corrosion resistance in a compact, lightweight fastener. Electricians, electronics technicians, and control panel builders rely on this type of standoff to secure boards at a fixed distance from a chassis or mounting surface.

This standoff is suited for residential and commercial control panel assemblies, HVAC control boards, industrial enclosures, and any electronic assembly requiring rigid, threaded board support. The hex body profile allows for wrench tightening without spinning, making installation straightforward in tight panel layouts. Typical applications include mounting logic boards, relay boards, and terminal interface boards in electrical enclosures where consistent standoff height is required.

Key Features

• Female 4-40 thread accepts a 4-40 machine screw for board attachment
• 1.25-inch overall length provides consistent board-to-chassis spacing
• Hex body at 0.25 inches across flats allows standard wrench or nut driver installation
• Brass construction offers good electrical conductivity and machinability
• Clear zinc chromate finish meets ASTM B633 Type 1 and QQ-B-626 Comp 22 for corrosion protection
• Sold individually, compatible with standard inch-series fastener systems

Compatibility

Designed as a standard inch-series female hex standoff for use with 4-40 threaded fasteners in circuit board mounting applications across electronic and electrical enclosures.

Installation Notes

Installation is performed by qualified electricians or electronics technicians. Power down and de-energize all circuits before working inside any enclosure. Use an appropriately sized nut driver or open-end wrench on the hex flats to tighten without damaging the plating. Follow applicable NEC guidelines for control panel assembly and ensure mounting hardware is torqued evenly to avoid board stress.