Electro Hardware P529M01F21-440 Female Standoff 4-40

Product Description

The ELECTRO HARDWARE P529M01F21-440 is a round female standoff designed to create precise spacing between circuit boards, panels, or structural components in electronic and mechanical assemblies. Machined from brass with a zinc-plated finish per ASTM B633 Type 1 and QQ-B-626 Comp 22, this standoff accepts a 4-40 thread and measures 0.5 inches overall length with a 0.25-inch outside diameter. The fully threaded interior allows a fastener to engage from either end, providing a secure and repeatable mechanical connection. Electricians, electronics assemblers, and panel builders rely on this type of standoff for reliable board-level mounting in control panels, enclosures, and instrumentation chassis.

This standoff is suited for use in low-voltage electronic assemblies, PCB mounting configurations, and control panel fabrication where tight dimensional tolerances and corrosion-resistant hardware are required. The zinc-plated brass construction provides good conductivity and moderate corrosion resistance in indoor and sheltered environments. It is appropriate for both OEM production runs and field repair of electronic control assemblies across HVAC, electrical, and light industrial applications.

Key Features

• Fully threaded female interior accepts 4-40 fasteners from either end
• Brass base material with zinc-plated finish meets ASTM B633 Type 1 and QQ-B-626 Comp 22 standards
• Round body profile at 0.25 inches outside diameter for compact footprint in tight assemblies
• 0.5-inch overall length provides consistent board-to-surface spacing
• Length tolerance of -0.005 to 0.005 inches ensures dimensional consistency across production runs
• Inch-system fastener sizing for compatibility with standard 4-40 hardware

Compatibility

Designed as an OEM-style replacement or production component for assemblies using 4-40 inch-thread female standoffs in round brass configuration. Fits standard 4-40 machine screws and mating hardware in electronic chassis, PCB mounting systems, and control panel builds.

Installation Notes

Installation is typically performed by electronics assemblers or panel technicians using a hex key, nut driver, or standoff installation tool sized to the 0.25-inch body. Ensure power is removed from any live circuit board or panel before installing or removing standoffs. Do not overtighten mating fasteners, as brass threads can strip under excessive torque. Follow applicable IPC assembly standards or project-specific mechanical drawings for correct torque and spacing requirements.