Electro Hardware P553M01F21-440 Female Standoff 4-40

Product Description

The ELECTRO HARDWARE P553M01F21-440 is a round female standoff designed to create a fixed, threaded spacing point between two surfaces in electronic assemblies, enclosures, and panel mounting applications. Machined from brass with a zinc-plated finish meeting ASTM B633 Type 1 and QQ-B-626 Comp 22 standards, this standoff measures 0.875 inches overall length with a 0.25-inch outside diameter. The interior is fully threaded at 4-40 to a depth of 1 inch, allowing complete thread engagement through the full body length. Electronics assemblers, equipment technicians, and panel builders typically install these fasteners during chassis and PCB mounting operations.

This standoff is suited for light-gauge panel work, printed circuit board mounting, and instrumentation enclosure assembly where a 4-40 thread pitch is specified. The inch-system dimensions and ASTM B633 Type 1 zinc-plated brass construction make it appropriate for both indoor electronic assemblies and light industrial enclosure applications where corrosion resistance and conductivity are considerations. The round body profile seats cleanly against flat mounting surfaces without additional hardware modification.

Key Features

• 4-40 internal thread, fully threaded through the 0.875-inch body length
• Brass base material with zinc-plated finish for corrosion resistance
• Meets ASTM B633 Type 1 and QQ-B-626 Comp 22 finish standards
• 0.25-inch outside diameter round body for compact panel layouts
• Length tolerance held to -0.005 to 0.005 inches for consistent stack height
• Inch-system dimensions; compatible with standard 4-40 machine screws

Compatibility

Designed for use with standard 4-40 inch-series machine screws and mating threaded fasteners in electronic chassis, PCB standoff, and panel assembly applications.

Installation Notes

Installation is typically performed by electronics assemblers or equipment technicians using a hex driver or appropriate standoff tool sized for the 0.25-inch body. Power down all equipment and discharge any stored energy before installing or replacing standoffs in live assemblies. Do not overtighten into tapped holes in thin panels, as brass threads can strip under excessive torque. Confirm mating screw thread engagement meets minimum depth requirements per the assembly specification before finalizing.