Electro Hardware S509-M01-F21-G Round Circuit Board Spacer

Product Description

The ELECTRO HARDWARE S509-M01-F21-G is a round, female unthreaded circuit board spacer designed to create a controlled standoff between a PCB and a mounting surface or adjacent board. It accepts a 6 screw and holds boards at a fixed overall length of 0.1875 inches with an outside diameter of 0.25 inches and an inside diameter of 0.141 inches. Constructed from brass with a zinc-plated finish meeting ASTM B633 and QQ-B-626 Comp 22 Type 1 standards, this spacer provides reliable electrical isolation and mechanical separation in control board assemblies across HVAC, electrical, and industrial equipment applications.

This spacer is suited for use in residential and commercial equipment wherever circuit boards require rigid, precise standoff mounting. Typical applications include HVAC control board assemblies, electrical enclosure PCB mounting, and any panel-mount scenario where consistent board-to-board or board-to-chassis clearance is required. The female unthreaded design allows a screw to pass through cleanly, securing the board without threading into the spacer body itself. Its compact 0.1875-inch length makes it appropriate for low-profile PCB stacking configurations.

Key Features

• Female unthreaded body accepts a 6 screw for straightforward PCB standoff mounting
• Overall length of 0.1875 inches with tight length tolerance of -0.005 to 0.005 inches
• Outside diameter of 0.25 inches and inside diameter of 0.141 inches with tolerance of 0.000 to 0.010 inches
• Brass construction with zinc-plated finish for corrosion resistance
• Meets ASTM B633, QQ-B-626 Comp 22 Type 1 fastener standards
• Round body shape for consistent fitment in standard PCB mounting hole patterns

Compatibility

Designed as an OEM-style replacement or new-installation spacer for circuit board assemblies requiring a 6 screw, female unthreaded round standoff with a 0.25-inch outside diameter and 0.1875-inch overall length.

Installation Notes

Installation is typically performed by licensed electricians or trained HVAC technicians during control board replacement or assembly work. Always de-energize the equipment and follow applicable NEC lockout/tagout procedures before handling circuit board hardware. Ensure mounting hole alignment before seating the spacer to avoid stress on the PCB. Minimum order quantity for this part is 10 units.