Electro Hardware S1391-M01-F21-I Circuit Board Spacer

Product Description

The ELECTRO HARDWARE S1391-M01-F21-I is a round, female unthreaded circuit board spacer designed to create precise standoff clearance between a PCB and a mounting surface. Machined from brass and finished with a zinc plating per ASTM B633, QQ-B-626 Comp 22 Type 1, this spacer delivers corrosion resistance and dimensional consistency in electronic assembly applications. It measures 1 inch overall length, 0.194 inches inside diameter, and 0.500 inches outside diameter, with an inside diameter tolerance of 0.000 to 0.010 inches and a length tolerance of -0.005 to 0.005 inches. The Number 10 screw size makes it compatible with common board-mounting hardware used in control and circuit board assemblies.

This spacer is suited for residential and commercial electronic control board installations, including HVAC control boards, relay panels, and general electrical enclosure assemblies. It is typically installed by HVAC technicians, electricians, and electronics assembly technicians when mounting circuit boards that require a rigid, non-conductive-style standoff gap while maintaining a secure screw engagement point. The female unthreaded body style allows a fastener to pass through cleanly, clamping the board at the correct standoff height without threading into the spacer body itself.

Key Features

• Brass construction with zinc plating per ASTM B633 and QQ-B-626 Comp 22 Type 1 for corrosion resistance
• Female unthreaded body accepts Number 10 screw hardware for secure board mounting
• 1 inch overall length provides consistent PCB standoff height
• 0.500 inches outside diameter with 0.194 inches inside diameter for precise fitment
• Tight length tolerance of -0.005 to 0.005 inches ensures uniform stack height across multiple spacers
• Round body shape for straightforward installation in standard PCB mounting holes

Compatibility

Designed as an OEM-style replacement or new-installation spacer for circuit board assemblies requiring a Number 10 screw, 1 inch standoff height, and a 0.500 inch outside diameter round brass spacer.

Installation Notes

Installation is typically performed by HVAC technicians or electricians during control board replacement or new panel assembly. De-energize all power to the control panel or enclosure before handling circuit boards or mounting hardware. Use appropriately sized Number 10 fasteners and a standard screwdriver or nut driver to seat the spacer without overtightening, which can crack board substrate. Follow applicable NEC guidelines when working inside electrical enclosures.