Electro Hardware S789-MO4-F16-E Circuit Board Spacer

Product Description

The ELECTRO HARDWARE S789-MO4-F16-E is a round, female unthreaded circuit board spacer designed to maintain precise separation between a PCB and a mounting surface or adjacent board. Machined from aluminum grade T-3 to the QQ-A-225A Comp 2 fastener standard, this spacer accepts a number 4 screw and holds tight dimensional tolerances suited to precision electronics assembly. Overall length is 0.1875 inches, inside diameter is 0.116 inches, and outside diameter is 0.3125 inches. The uncoated finish is appropriate for applications where bare aluminum conductivity or weight savings is a factor. Electronics assemblers and field technicians use this hardware when mounting control boards in HVAC equipment, electrical enclosures, and similar trade applications.

This spacer is suited for residential and light commercial applications wherever a number 4 fastener is used to mount or stack circuit boards. Common install scenarios include control board mounting inside furnace cabinets, air handler electrical compartments, and low-voltage control enclosures. The compact 0.1875-inch overall length makes it appropriate for tight board-to-panel clearances. The round body profile and female unthreaded design allow a screw to pass through or thread into mating hardware on either side of the assembly.

Key Features

• Female unthreaded, round body - accepts number 4 screw for secure board standoff mounting
• Overall length of 0.1875 inches with a length tolerance of -0.005 to 0.005 inches for precise stack height
• Inside diameter of 0.116 inches with a tolerance of 0.000 to 0.010 inches
• Outside diameter of 0.3125 inches provides a stable footprint on the board surface
• Aluminum grade T-3 construction per QQ-A-225A Comp 2 fastener standard
• Uncoated finish - no added coating that could affect fit or electrical contact

Compatibility

Designed as an OEM-style replacement or standard hardware component for circuit board mounting applications requiring a number 4 screw, female unthreaded aluminum spacer with a 0.1875-inch overall length.

Installation Notes

Installation is typically performed by electronics assemblers or licensed technicians during control board replacement or panel assembly. Always de-energize and lock out the equipment before servicing any control board or electrical enclosure. Use a hand driver or low-torque screwdriver to seat the fastener - do not overtighten, as aluminum spacers can deform under excessive load. Verify screw thread engagement and board clearance before restoring power.