Electro Hardware P537M10F21-440 Female Standoff 4-40

Product Description

The ELECTRO HARDWARE P537M10F21-440 is a round female standoff designed to create fixed spacing between PCBs, panels, and enclosure hardware in electronic and electrical assemblies. It features a 4-40 unified thread and a fully threaded interior, accepting a fastener through the full 0.625-inch body length. The 0.25-inch outside diameter keeps the profile compact in tight layouts. Constructed from Grade 2 steel with a zinc-plated finish that meets ASTM B633 Type 1 and QQ-S-633 standards, this standoff delivers corrosion resistance appropriate for indoor control panels and electronics enclosures. Licensed electricians, panel builders, and electronics technicians are the typical installers.

This standoff is suited for use in residential and commercial control panels, electrical enclosures, and PCB mounting assemblies where consistent board-to-board or board-to-chassis spacing is required. The fully threaded female design accepts a machine screw from either end, giving the installer flexibility in stacking or layering subassemblies. Its inch-system dimensioning makes it a direct fit for standard 4-40 fastener hardware used throughout North American electrical and electronics manufacturing.

Key Features

• 4-40 unified female thread, fully threaded through 0.625-inch body length
• Round body profile with 0.25-inch outside diameter for compact panel layouts
• Grade 2 steel construction provides reliable structural integrity for mounting applications
• Zinc-plated finish meets ASTM B633 Type 1 and QQ-S-633 corrosion-resistance standards
• Length tolerance held to plus or minus 0.005 inches for consistent stackup height

Compatibility

Designed as an OEM-style replacement or new-installation standoff for assemblies using 4-40 inch-series machine screw fasteners in PCB mounting, panel fabrication, and electrical enclosure applications.

Installation Notes

Installation is typically performed by licensed electricians or electronics technicians during panel assembly or PCB mounting. Power down and de-energize any assembly before installing or replacing standoffs. Use the correct 4-40 driver or hex tool sized for the 0.25-inch OD body to avoid deforming the standoff. Follow applicable NEC guidelines when installing standoffs inside listed electrical enclosures.